Aquatic Plant Forum banner

PPS Discussion Thread

18000 Views 48 Replies 16 Participants Last post by  Jeff Kropp
Editors Note-

We at APC do not normally step in and edit posts or split threads with out a reason. We feel that Discussion of the PPS Method warrants it's own thread and should not be mixed with the actual article.

Original post starts below

Water, fish, plants, biology and ones individual ecosystem that are created in your rooms are not standard, they are not the same, and they are not generic. Each has a life of their own and each is unique in both design and water chemistry. Accordingly, the Perpetual Preservation System was born from this idea. The idea that your tank is different, the idea that your tank is unique and that it requires unique attention is what brings us to where we are today in terms of aquatic plant fertilization and maintenance.
Are they really unique as far as their needs?
Plants need the same things pretty much, Light, CO2 and nutrients.
Assume maximum rates, then anything less than that will still have a good supply(eg non limiting)

Not that unique..............
Routine mainteance/water changes can standarize things for everyone everywhere. Actually they have and have for some time.

If you add "just enough" for your particular "unique" tank you end up walking a razor's edge. While it's possible to add just enough with time and skill and watching the plants a lot, it also requires lots of testing, RO water, calibration of your test till you get a feel for your unique tank.
I've done this, so have many many aquarist before you.
Reef folks do this and I keep those as well.
I hear their sufering quite often, meanwhile I do a simple water change and don't need to do even 10% of the expense, time and work to have the same results.

This introduces a large amount of variables and work.

Over the past months I attempted to get this point across in many posts here on APC answering a question at a time, a parameter at a time, a topic at a time which caused confusion. Your aquatic systems are not standalone; they can not be analyzed alone, they must be looked at in its entirety as a whole.
So go from light=> CO2=> NO3=> K+=> GH=> PO4=> Traces
If those are addressed, that's pretty much all plant needs.
The rate of uptake and light(or CO2 or NO3 or PO4) that drives the system relates to the balance. This is true in marine systems, non CO2 plant tanks, lakes/ponds, rivers, anywhere there is good plant growth.

You can test each individual system and find some it's unique needs and dose accordingly.This involves a lot of testing. Many will never do that. The other issue, while testing is useful, the rates of uptake depending on biomass changes, pruning, water dosing errors etc make testing a long term project.
You will slip up and neglect a tank at some point. Adding more things and steps make this far mopre likely.
Simple is good.

After some time, folks can use their plants as indicators to see that things are fine or need work. Or they can simply go on as they were and waste a little trace/KNO3/KH2PO4. That's dirt cheap. But then it gets back to testing again. You chase the test, why wait till something is getting too low? Why wait till you start to see holes in ther M umbrosum? Some folks get good and can predict this before it occurs by watching the growth rates. That's not something that is easily learned or shown to a new person, it's learned from screwing up and trying to anticipate. Or you can test (and hope you tested the right thing/reading, be sure to calibrate etc).

But to what end? What do the test show you? Why are you dosing these nutrients to begin with?

To maintain a stable nutrient level for the plants?
To see what the plants use?

I understand the PPS, correct me if I am wrong, to mean few water changes, use only when needed or things get out of whack. Then dose and test to replace the nutrients as they are used up.

Add just enough nutrients.

Many will not calibrate their test kits. Many will neglect testing and slack off.
Many will not prune for a long peroid, many will not be able to afford or otherwise spend the $ on the test kits. It's asking a lot from someone for what?

Diana Walstad's arguement for the non CO2 method is extremely strong in that regard. No kits, no water changes, decent plant health, growth etc. Low maintenance. Supply of nutrients(fish food+ some from the substrate initially)=outputs(plant pruning). I differ with her on some points, but the overall notion is very very strong.

TE build up can cause a number of problems, we see this is reef tanks with Cu, they also, much like this, try to avoid water changes and dose only what is needed. They also do a heck of a lot of work to achieve this and at a considerable cost. Do you test for Cu? Or just Fe as proxy for all the TE?

On your dry weights pie wheel, 13% is NO3? NH4? or Total N?
My references are about 1.5% N.

I'm still trying to find some utility beyond fewer water changes.
I know you have put a lot of work into it, been there done that, still do that, but what is the goal? Good plant growth with the least amount of work? I did all that testing for years and still do it, but to answer certain questions. I want something out of my work.

Otherwise I'm doing the testing for no real reason other than to avoid a few simple water changes. I tried that. At lower light it works fairly well, any system does, I don't do any water changes of the non CO2 tanks. If I'm going to do the work and go through all that, I want something out of it. I used the rates I learned from the testing on many tanks and plant species(close to 250-300 now) to determine a simple dosing method using water changes and tap water.

This works on just about any tank, from Zambia to Australia. It works because it addresses these unique differences by assuming the tank at max light. That covers all the bases, but assumes that the higher levels will be fine, this proved to be fine regarding algae and toxicity levels build up for all the nutrients and organic by products that reduce O2 levels, not just one trace element and the kits you have on hand.

Then folks can reduce the nutrients down to suit their unique needs based on plant health, rather than testing. Water changes with tap water are easy to do, then dosing thereafter makes it easy. That answered my question and solved this issue without the need for test kits, without introducing a huge work load, without so many unknowns and expense to the hobby. It is good to test for some things to reduce the amounts of KNO3 you may need, I have a good feel for various light levels and rates of uptake, CO2/non CO2 approaches. Yep, it took many years and work and discussion as well.

I'm still not clear on what your goal is here besides reducing water changes through lots of testing and long term reliance on the test kits. Can you discuss that aspect in detail and the reasoning behind it?

Tom Barr
See less See more
Not open for further replies.
1 - 14 of 49 Posts
IUnknown said:
I think one good thing with this method is the information on Ca and mg. I've got the test kits coming in a couple of weeks, so I'm not sure its my problem, but at least the information has given me another place to look for answers to my leaf curling/stunting problem.
Yes, it's good to have, Steve Dixon and I did some Gh work back in the 1990's as the SF tap water is notoriously low (0 to 20ppm).
He added Mg and Ca and after seeing my tanks and tap water switched to adding more GH.

There is an old article on sfbappas site to this effect with very soft purer waters.

Up take rates can be used and useful for Ca/Mg if you plan on adding "just enough" but I see no utility in adding just enough or testing for it unless you know there is an issue. I used a wide variety of tap waters with enormous ranges over the years, I've never found found issues unless the Gh was too low.

So adding plenty to never have it become limiting has been much easier than testing.

I can add just enough NO3 to a tank also, but why?
Why walk this fine razor's edge? Does higher Ca/Mg cause algae? Hurt plant growth, if so which species? I have no seen any GH related issues at high GH in any plant species, KH I have seen with 2-3 species better growth at low KH's, but not GH's. I have plenty of dosing experience with Mg as do many being part of the PMDD program.

Neil and I discussed Ca for many years, he has very soft tap water as well.

I've found plants do much better with higher GH's.
Same thing for KH, but there are 2-3 species that seem to grow "better" at lower KH's.Most plants will grow better as there is an ample supply of DIC Carbon.

This makes me question the utility of GH measuring unless you have a gaol of minimizing the additions of Ca/Mg for some reason.

Can you better pinpoint the rates of uptake and predict the ratios? Sure, not sure why you would find that useful though nor gain much from knowing that.

Testing is great and all, but to what end? You can rule it out I suppose, but I've said that years ago if it was in excess and high enough, 50-100ppm or so, then you don't have much to worry about. If you still suspect something, add a little MgSO4 as Ca is virtually never in excess to Mg in any tap water.

If you use RO, then you neeed to add all the KH/GH components back, that's a PITA but too bad once you get use to it. You add 1 tablespoon of CaCl2 and 1 Tables spopon of Baking soda or Potassium carbonate etc, 3/4 teaspoon of MgSO4 to your tank after each water change and then you are done, it's standard.

If you want to push the water changes and not do them....then this information begins to become useful and you'll still need to test......

So there are trades offs..........

I'm not sure these are worth all the testing and seeing how far you can go without messing things up at higher growth rates.

You can test to check to make sure Ca/Mg do not louse up and become limiting.........

But after testing and all and calibrating the seems easier and cheaper to do a water change.

Why avoid the water change? Seems like a self imposed barrier to me.
I've tried as have many others with good test kits(All lamotte and Hach) to try and add only what the plants will use and avoid water changes. I know the mentality of it and results. It's 3easy to do with non CO2 methods and as you increase the light, CO2 you increase the uptake rates of the plants.

Edward is entirely correct about each tank having a unique uptake rates, plant species etc. Uptake rates in a tank will less/more than another.

Plant specific uptake rates also play a huge role.

But these rates are not a problem nor need monitored if you add a standard solution back into the tank each week and do the large water changes.

All that monitoring cost you money, time and work.

Water changes removes many of the unknowns, need for testing in the first place(something that is very tough to get folks to do for even the most basic things such as pH/KH, many still don't measure KH routinely)

One area I would suggest that would be very useful using PPS, monculture of specific plant species.

That work would be useful, in addressing plant specific issues and appearances without infuences of other plant-plant competitions.

But not everyone wants a single species plant tank:)

Tom Barr
See less See more
Its me [color=#175172 said:
I have two tanks, 53gall and 15gall. It takes 1 hour and 30 minutes to change water in both tanks and it takes 5 minutes to test water in both tanks and take notes.[/color]

It takes how long to do drain and replace 35 gallons worth of water?
It takes me all of 10 minutes to do 50% weekly water changes on tanks that size. I use a siphon hose and out the water goes, drains in minutes, I add a hose to refill(I use tap), I don't touch a bucket. Done, I can do water changes on my lunch hour for 5 tanks, totaling 180 gallons in 35 minutes and still eat lunch as they fill.

2. Some of us in SFBAAPS work even harder at being lazy, we have automated water changes.

A simple 1/4" tube and led to a drain with timer shut out solenoid, a float valve(manual type of electronic) refill with a 1/4" tube.
Easy, simple, cheap and it's simply hard work being that lazy!!

3. I can say it takes me 2 hours to test, 20 minutes to do a water change.
I can come up with extremes, most folks are not that slow at water changes.

I'd figure out an easier method to do a water change personally, but you can do a water slow as you want, that's _your choice_, not an arguement nor is "easier" or "faster".

I've been there done this a long long time ago.
You guys want to argue and reinvent the wheel with a different name, feel free.

If you seek to get out of work, an automatic water change system is easy and works. Dosing EI works for the rest.

If you want to get out of even more work, use automatic dosing pumps.

I really am trying to think why it could possibly take you __so long__ to do a water change........???

So you can test Ca, Mg, KH, NO3, PO4, in 5 minutes?
But it takes you 90 minures to change 35 gal of water?

This assumes the kits are accurate also and/or calibrated.
We will assume that to be the case.

Folks need to do that as well and make standard solutions, most are scared to death of chemistry and their eye glaze over. They are scared of KNO3, KH2PO4, CaCl2, and adding all this metrically weighed stuff into 500mls of water.

It's hard enough telling them to add "1/4 teaspoon of this jar 2-3 x a week".
Try telling them to calibrate and make a standard solution. Sure a few brains will, but most will go "uhhhhhh......I did not take Chemistry"........

I try to make it easy, cheap and simple for folks.

Now.. Please explain to me what is so wrong with testing?

Nothing "wrong with it" per se,

1.Folks did not get into this hobby to test.
They get into it to have a nice planted tank, gardening, nicer place for the fish etc.

2.Folks buy junky test kits, folks believe junky test kits to be true and accurate, that's caused huge issues for many years/decades. They buy PO4 removed, worry about NO3, Fe especially... ad nauseum.

3. Folks don't like to test as rule, trying to get hobbyist to do this consistently is highly difficult. I worked at a LFS as kid, I suggested this, few ever did it. They brought the water samples to me to test it and we charged them for this service, that's pretty common.

You guys should offer your testing services:)

4. Test kits cost a fair amount(decent ones) and are an added expense many do not want to invest it. People are cheap in this hobby.They will look for other alternatives before spending the $, a few will, but many will never test no matter what.

5. You don't need them, they are nice for some things, they are useful for research.

Like, I find very interesting the Estimative Index too, but I really can't see any problem in trying a system where you don't change water, or the water change is not so frequent.
Me either, try a non CO2 tank sometime since you enjoy no water changes.......

You can try and push things and not do water changes, try and test things and see waht you are missing etc and dose accordingly.
We all have done it to some degree over time.

You will never grow if you do not try what you have already not mastered.
I know both sides of this coin, this applies to CO2 enriched tank, high and low light systems, high low bioloads, you pick a method, even Saltwater and reef folks. I've been at this for a long time and at in a large way.

I've never said something this generalized, I've said for many years, non CO2 tanks do not get water changes for YEARS. I have such tanks. I've tested them in the past, I really do not care to test something where I'm trying to reduce the work load on it already.

Many folks have tried to add only what the tank needs and avoids water changes with CO2 and high light. They crash their tanks, have algae and other issues, they might get away with it for awhile, but generally the tank will be a better healthier system and garden with water changes rather than avoiding them. Even some of the best observational folks and scapers I know acknowledge the problem in CO2 enriched systems lacking water changes over extended peroids of time with higher light.

Plantr health is often healthier as a result, that's the ruler folks might consider.

As far as testing, higher light and more CO2 will drive the uptake rates faster and you can see what nutrients are used up much quicker and get results
that assume the fastest rates, that's a max amount needed.

You are certainly welcomed to try it or any method, been there done that years ago, I'm just asking why and how is it easier.

If you reduce the light down, it'll work better.
If you go non CO2, it'll work great.

How do I know these things? Humm.......

I know Tom, you will come up with a very good argument, but admit it please.. there is nothing wrong with testing.

Hehe, I will?
Okay I admit it.

Okay there's nothing wrong with a bad test kit that gives an incorrect readings that I do not own because I'm too cheap to buy them and I'm too lazy to use because I have an automatic water changes and it takes me 5 minutes once a month to fill the autodosing reserviors and I really need to test my non CO2 tanks often to maintain their "balance". I also hate chemistry and do not know anything about it and feel I do not need to know any of that high flutin intellectual jargon to grow plants:)

Otherwise test kits are very useful.

They do have their uses, CO2, but even that has some limits. They are useful in determining uptake rates for certain plant species, groups of plants to a much lesser degree, for finding out a routine such as the EI, it came from test kits so that other did not have to go through this again.

Why did we come all this way? Why did we come down from the trees?

This might bother people as much as adding PO4 did some years ago when I suggested that controversial notion......

I've never said testing is bad, I've said some test methods and some test kit kits are bad. I have said you do not need test kits for things except for GH/KH/pH.

Besides, you have lots of experience, and you also agree with the fact that calibrating a test kit will lower the chance of bad reading. Now arguments like "lots of people will not calibrate their test kits", is entering into people heads and figure out the future. Assuming you're not on the voodoo/black magic scene, explain to me what is so wrong with testing.
The High priest of voodoo suggest you read the above for a reference.
I've nagged folks to calibrate their kits some 9 years ago.
So yes, I do get inside an aquarist head ask basic questions about what seems reasonable. I do recall how many folks really did it.

No voodoo needed there, I called it common sense about people.

But testing the heck out of your water to what end?
To avoid a water change?To avoid work?
To see about uptake rates?
Does it make the plants grow better?
Is it something folks will do and continue to do?
Is it cheap?
RO water is a PITA for tanks and especially if you have many of them.
Another item you do not need.

I need a reason to test and do all this work.
I'm lazy and want to avoid work, not chase after it.
I certainly don't want to remove things from tap water and then add them back again.

So how is this easier than an auto water changer and how is it cheaper??
RO waste lots of water also. So you pay what? 90% more for the water change assuming a reject rate of 90%.

The critque still stands and no one has said much.
I think you've dug yourself in deeper.

Auto water changers, now there's a lazy person's nirvana....

Tom Barr
See less See more
defdac said:
You told me this when I asked about this over at APD:

"The above references are for terrestrial plants, which have no ionic Ca++ floating around their leaves(from water+ CaCl2 which disassociates into their ions Ca++ and Cl-)"
With very low circulation that would be a problem I guess?
Traces I have enough of. The substrate is another matter. Perhaps I should try shoving down some CaCl2 by the roots and see if things get better - but if the plant have to transport things from the roots/older parts I guess it would still get curly leaves?
This whole thing of certain plant specific problems with certain plants is not a PPS issue.

This is more a specific dosing issue.
Aquatic Plants do not use Ca++, Mg++ from the substrate in nature nor in lab studies. So if you have enough in the water column, that's where it'll come from.
While you can test to see what you over looked, often a poor NO3 test or too low NO3 levels will cause issues similar to Ca,

Pearl grass is friggin weed, so is Rotala var green, if you stunt it, it takes a long time for it to recover. Same for Ammannia.

You need to be specific with the plant species. Testing can help as a good test kit and modification of your dosing routine can help to adjust for some funny plant's tolerances.

Generally in virtually all cases, folks need to add more nutrients, not less.
This can still be done with PPS also.

So you can see how the long term excesses influence plant growth over time without water changes. Still, I can add the nutrients back and keep them more stable using water changes and dosing.

Otherwise you end up chasing the nutrients with test kits and not being able to amintain a good standard reference solution without the need for lots of testing and other unknows such as oragnic interactions and by products.

While using RO removes some unknowns..........not doing water changes also introduces other unknows as well.

I can test inorganic ions, I cannot(well, I can, but few hobbyists use organic chemical testing) test for organic compunds of whichb there are many and how they influence things is very debateable but liltte has been done on it.

Most foplks that have tried not doing water changes and dosing had much better success by doing their 1-2 week water changes 40-50%.

That's not me, that lots of folks that tried to avoid water changes with a nice healthy planted tanks over time using CO2 moderately high light. After trying this for a few months , years, you'll figure it out and see for yourself.

Tom Barr
See less See more
Its me said:

Tom, there are a couple of things here you say that makes absolutely no sense at all; you enter in people heads ? You kidding me right ?
I'll let you answer that one:)

Need to know a lot about chemistry? Ok, here goes my experience now: not much people here try chems on their tanks, so talking with them about PPS, EI or PMDD is the exact same thing (chemistry is not the issue here).
Okay, which is easier to explain to someone?
Add 1/4 teaspoon of this "fertilizer" 3x aweek or..........

Test your NO3, calibrate this test kit and make known standards for these and also test 6 other parameters in the same way? You still dose both.

This is simpler than PMDD and PPS and over the long term, works better as far as plant health/growth is concerned.

I've tried to talk chem with folks, they freak. Some get it, many don't.
So if we say add 3 basic things, 4-5 if they have soft water, then it's easier.
If we call them ferts and add 1/4 teaspoon of this 3x a week, no chem involved.

Simple, easy and less pain. Results.........they are very good. If you do this simple routine, the results continue.

Not everyone wants to do water changes, fair enough, there are trade offs associated with that. What these trade off are is the focus of this thread.

What trades off seem reasonable to you is subjective to some degree, but what you trying to acheive with these trade offs?

Less work? Simplicity? Research? Better plant health/growth? Less algae?
Fewer water changes?

These are basic questions as to what your goal is.

So, all test kits are way bad. Ok, i assume you have tested them all, and i wont fight with you about this, after all... you invented the weel (sorry to talk so much about the weel but i found the expression hilarious).
Me too:) all kits are not "bad", all kits should be run against a standard though to see if they are off scale or bad.
Many folks will never run their test kits against a standard, they will ask is this kit good or not.

No, I have not tried ever kit brand, I like Lamotte and Hach as far a somewhat relative reasonable costing hobby kit to suggest.
These have proven the best for the water monitoring industry and Reef aquarist who are far more inclined to drop $$ for testing, invest the time and to avoid water changes. Salt cost $$ so water changes are a balance there.
They still do water changes no matter how careful they are.
Even the top people do this. Amano does it. I do it. Reef folks do it.

Ask yourself why.

Automatic water changes: want me to put tubes around the living room, or put them inside walls to hide it ? Yeah right.
I drill into the wall and run them underneath, once done, I do not have to fool with it from then on. 4 hours saves me 400 hours per year and the water changes are consistent.

All I do dose some dry ferts, take 4 minutes a week.

You do not have to do this by any means, but you said the water changes were a problem.

If it takes you 90 minutes to change 35 gallons of water, that would be an issue for me too.

You create your own set of barriers to your own solutions.
I use to do that. Jedi mind trick or common sense solution to the problem?
I'm not poking fun at you, I'm asking you to consider what you are saying.
I've been on both sides of this fence. I've done both methods for many years. So have my friends.

Take in consideration Tom, you might have lots of experience, no one is telling the opposite, now assuming all your theories are right, and the rest is wrong, man.. you will need the voodoo to help ya out.
Being humble aint that hard to be, even for weel inventors. :)
Best Regards
Personal attacks are not arguements of support.
That's what politians do, not scientist.

I'm not saying this is "wrong", I'm just asking to what goal do you hope to acheive? What is the purpose?

That is a very humble question and seem to have been lost in the personal issues.

To date, no one has offered a supportive answer.

I can suggest extremism on either side to make a case.
I am practical and solve things that make life easier and the plants grow better.

I'm trying to see what this has to offer that we have not already done 100 times long before any of you even had fully planted tanks. Myself included.

I have yet to hear anything new or a new method.
I do see an updated method that includes more testing, calibration of test kits etc, that's good if this method is your goal.
But folks used Lamotte and Hach kits years ago and tried this and these kits are pretty darn good and accurate IME/IMO.

Tom Barr
See less See more
gnatster said:

In an effort to clear up confusion and misunderstanding would you be so kind as to create a new thread entitled Estimative Index (EI) and detail the process for all. Once created I will happily sticky it in the Fert Forum. I think this will help people to see another of the various methodologies available.


My points about PPS, I've done this and have made comments about how it worked, or did not work for me. I've tried it with CO2 , non CO2 and with a battery of Lamotte and Hach kits, so have other folks from year's past that no longer post on the APD. I've tried it with several ranges of light intensities.

These are comments directly related to this PPS.
It's nice to organize it further and make it more of a "method", but folks have been doing this for a long long time already. If you look back into past folk's experiences rather than folks with only a few years, you'll see some neat ideas and some things folk's learned.

It's better to learn from long as it's not your own.
This is one reason I post.
I suffered but am able to try new things to solve the problem and take a new way to look at the problem.

Some things folks can do......and avoid testing and approach it from a non CO2 prespective. No testing needed there.

I suggested that. I also know folks that have tried no water changes in high light CO2 tanks, we all slack off and try and dose over time and can see the results. They often are algae or stunted slowed growth.

Many very very good observational people have done this over many years. They watch the plants carefully and add what is needed.

Plant response is key.

This is one reason such a system will work in a non CO2 tank where uptake is lower do to CO2 limitations and lower light.

This is PPS exemplified. Or is it DW's apporach or is it a non CO2 approach?
Dosing PO4 to excess, is this EI or is it PPS?

The lines blur here.

These are some of the points I've made.
I'm not suggesting any method is "worse" or "better".

But there are trade offs for each main method and more wiggle room when you use less light, slow things down, don't add CO2.

These trade offs might be worth while for you or they might not.
I consider folks going through this testing process a "phase".

I do like to test a great deal for the record. But only if I am trying to answer a specific question, not as part of a routine. I want something out of my work efforts.

I realized that I did not have to test and could guess the rest of the week by doing large water changes.

Folks had issues with test kits, most still do.

Perhaps some day folks doing this will get lazy and wonder what good is all this data from the testing.

Not doing water changes introduces a number of unknowns, those assumptions can get you into trouble when you try to interpert things.

I have no idea why it takes some folks so long to do water changes, I add a hose, drain, add another hose, fill...or... automated water changes.

Those issues are easy to address.
It removes many assumptions and requirements.

Then there's a practical part: does it work well?

You try PPS at 4 w/gal for a year with no water changes and you try EI for a year. I'll let you decide for yourself.

Sharing info is good, I am doing that here in this thread. It seems I've considered both sides and few side of the coin many have not.

I'm asking why is this useful and why is it being used.
I asked myself this same question as well a number of years ago.

I tested some non CO2 tanks a few years back. I found they needed more K+, Ca, Mg, a little traces and fish food could do the rest. I added PO4 also, it had little effect on plants/algae.

I ended up adding SeaChem EQ as it had most everything I needed, and a pinch once a week added what helped the plants out.

Edward suggest adding GH(Ca/Mg) etc.

That mirrors the suggestions and what I've found also.

But I'm not going to test just to get out of work.
I do not do more work get out work.

Tom Barr
See less See more
pineapple said:
Do you mean: Pearl grass and Rotala var green are hardy aquatic weeds. If, by some amazing chance, your fertilizing regimen causes stunting, they take a long time to recover.

Eats shoots and leaves
Andrew Cribb
No, I was specific with Rotala, if the NO3 is allowed to to drop, Rotala will not recover quickly. It'll grow like wildfire if fed.

Yes. Pearl grass is a weed, if you have trouble with that, something major is up. Go down the list, CO2, NO3, PO4/K, GH, traces.

Add more than you have been.
You should see responses quick with that plant.

You missed something and over looked it.
You can still do the PPS, just do a water change and re set things and keep going.

You can always revert back to EI to re set things and then start down the PPS path to whatever end suits you.

Tom Barr
See less See more
aviel said:
I have a high light high CO2 tank with all the nutrients and everything. I think NO3 consumption in this tank should be 5 ppms per day.
I think you are expecting a lot.
I'd shoot for 2-3ppm per day.
Substrate will play a larger role in PPs methiods and NO3, eg the denitrtification factor begins to become more of an issue and organic forms of nutrients that get bounded and complexed as the time passes from the last water change.

Here's a little trick you folks can use that enjoy the PPS method to remove this assumption with organic waste by products: activarted carbon, change and add this 1-2 weeks.
This will remove a lot of the organic fractions.

I told you folks I've done this in the past........
I got more tricks to be lazy and still get around issues.........
It's hard work being this lazy........

But I also know that if something goes wrong with the traces the consumption rate could be absolutely 0 - nil !! So I have to be preapred to both extremes... So I do my weekly 50% water change and add 5 ppm no3 per day. After all I don't want the no3 to bottom out before the end of the week - right?
No danger of that in your case.

So I add the full 5 ppm daily. Now if the tank consumption is 0 then by the end of the week I added net 35 ppms.
Test kit test kit test kit.
Brand? calibration? Accuracy?

Even at this 35ppm a week consumption(if we assume it to be correct, I doubt it highly) the plants will still not show signs of N issues.

Then to top that off, you do have fish and you do feed them.....?
More N from that. 5-10-ppm? I'd say at least.

So somethings are NOT adding up.

Now if I keep this routine I will have a tank with 35 ppms after water change and 70 ppm before next water change. Is that how I am supposed to grow my plants?
Huh? No you won't, the math behind a water change:

More about things other than now you need to test several things, not just NO3.....

And all the time I have no idea that something is wrong over there. And if I test for NO3 and it's high - shouldn't I test PO4 to see maybe this is the reason? And KH?
Now you are seeing the issues involved, they can be overcome with a lot of testing perhaps......but much less so with high light+ CO2 tanks.....

Something I have said from the start...........
See non CO2 methods for real PPS systems.

If you look at Edward's tanks, most are low light.
I recall one 4/w gal tank. the rest are low light by many folk's standards.

That is a huge issue when addressing this concept.

Moreoever, I have a 190 gal tank - 50% WC takes 2.5 hours.

See automatic water changes.
It's easy to set up and it can occur slowly(preferred method), even if it takes 5 hours at 2 am till 7 am, so what?

You are not doing it.

I change a 350 gal tank, 80% weekly, takes me 45 minutes.

I have no idea what you and others are doing with the water changes, but dues, figure out a simpler water change routine!

Hard plumb a drain and fill valve.
Alan has a RO system set up for fhis 90 gal discus system.
Takes 6 minutes to do 80% including fill.

It takes time to set this system up but the results are better for the fish and plants.

And for you and the time you spend.

Automatic water changes are not that complex.
SFBAAPS folks have this on larger tanks.

They spend zero minutes doing water changes.
They spend zero minutes testing generally unless CO2 appears low, then KH, pH if they do not have a pen or pH monitor.

End result: more time enjoying gardening, aquascaping, fish, new plants, less time testing........

Water changing removes those unknowns and the assumptions that come along with it.

Your experiences with testing and NO3 are very common.
Often the results do not make sense, you can ask why and try and figure them out.

That's sometimes fun but tough to find out what is exacly going on with all the assumptuions that are built into it. It's going to go back to the whole Allelopathy arguement.

That occurrs with plant - plant intereactions, so you have to address what? 300 dang species of plants that all produce how many different compunds?

I think you will be very hard pressed to tease that issue apart, at higher growth rates, the plants will produce more of these compounds.

Tom Barr
See less See more
aviel said:
That approach could work if you know your consumption rates - if you are absolutely sure that your no3 won't bottom out because there's no reason for it to decrease by more than 1 ppm per day. But us newbies, when something is not pearling - we need to test, and check, and double check - no?


I've addressed this issue with some 250 species of plants.
That's no small feat.

How did I do this?
You use the brain, assume the maximum rates will be the most any plant will use. Add many fast growing plants to a tank, jam lots of light, CO2 and then start in on the nutrtients one by one.

I never did the traces individually, why would I?
Folks seldom add them seperately.

I did this for CO2, 30ppm seems good.
I did this for NO3, 3-4ppm per day is fairly dang high, I've seen drops of 8ppm in a day in rare cases.
PO4 varies, but issues are not a problem unless you bottom things out, still much to done there with PO4. I had rates from 0.2ppm per day top .8ppm per day. Other preciptation issues need to be addressed.
K+ is assumed to be at a 4:1 ratio with N, that's for Terrestrial plants though.......even so, even if the difference is 2-3x as much, you still have enough K+.
Traces, once everything else is well ablanced, then you try volumes of traces/unit time/gal of tank.

Test kits suck for Fe.
I've detailed those issues out for years.
How do you address that one?

But the issue of what is the max rate, then assuming that it will never be beyond this amount......that is a GOOD assumption.

You can create test and figure stuff out much more easily by making good reasonable assumptions.......

That testing that acheived this data with a wide variety of plants, that is useful testing.

You folks do this yourself, and tell me I don't like testing or try to avoid it.
That is a lot of testing, but I know what I need to know and answered my original question.

Now others do not have to suffer this same faith.

Tom Barr
See less See more
gnatster said:
Why must you assume that any other way but the ways that you espouse here Tom are causing others suffering?
Folks(not you) have said that it takes a long time to change water.
I responded to those comments specifically.
I gave as you like to say, "alternatives..........." to the issue.
You can chose to do it this way, but those are choices, much like doing water changes. I discuss those trade offs, that's very relevant to the discussion.

If you like to test, go for it.
I use many different methods at the present time. Not just EI.
I test all day at work, I just might like doing it.


No one has responded to the organic issue or would the addition of activated carbon help or not...........what about mulm build up?

What about high vs low light?

"I can assure you that I am not suffering when I test my water, make stock solutions, spend more then 5 min on a water change or work with others that also find some or all these activities enjoyable. "

I like them too, but not everyone does.
I love a good hacking.
My own tanks are not enough, I'll go hack other folk's tanks as well.
I love to watch it grow in, I love to see how certain plants and respond to different treatments.


Never said you were suffering, many folks trying it out might not see it that way. We sat around talking test kits and variables for a long time back 10 years ago. Some did water changes, some didn't.
We were all local and had different tap water, but all had a battery of good test kits.

The ones that did not do water changes and tested a lot did well, but not as well as the one's that did the water changes. You can simply compare the plants and see the differences.

That was group consensus, not my own.
The plants did not lie though.

It is a flash back to 10 years ago and then a decade or two before than with Dupla about the time I got interested in it and then even further back in the mid 1970's and before in Europe.

If someone wants to try to tweak and improve the method, any method, they will want to try new things. That's why you test is it not? See if something works or not.

If you are satisfied with the status quo and happy with the results you have, then stick with it I'm a different person than that, but that's fine if you are that way.I was for some years.

You can use that method as your control and try other things. then you'll know if dosing PO4(or whatever you chose as your variable) will work or not. Many never thought to do that a number of years ago and I got poo pooed then merceilessly. Now you add it:)

I've tested the non CO2 for awhile and found ways to improve upon that, ways to improve upon the reef and refugium tanks, marine plants, low light tanks, folks have issues and seek to better their methods and systems.

This ain't EI vs PPS or any method.
It's about approaching things and figuring them out so you can improve upon your method. You can still test all you want and not do water changes.

There are other variables you can change around to explore things.

"I find something therapeutic about doing water changes. Not all of us are looking for ways to take what some feel is a less desirable endeavor and automate or speed up the process."

Precisely, but the flip side is that automation and less need to work on the tank's maintenance. I like water changes as well. But I also like to have tanks with different methods.

Having explored many methods allows a greater understanding of them.
I suggest folks try this also, I suggest they try non CO2, marine and other types of methods.

The other side is the non CO2 tank, that slows the process down.
Folks can address the concept of no or minimal water changes at various speeds.

I know the method and if someone wants to do it, I can certainly help them achieve that. There are trade offs, some are willing , some are not.
I discuss those trade offs.

I have also suggested a number of things that will help and improve things and better understanding about what is going on with this method.

Oddly, you have not acknowledged that part.

Tom, please try and see there are other views and they work.
See? See what? See they are no different than what many folks did 10 years ago? Those methods "worked" as well. They still yank out lots of weeds for the auctions. Come on down and see for yourself. Gomberg has not done a water change in 3 years years and his fish have bred.
He's been doing this 15 years before you even considered it.

I've done many methods including this one. You ask me not assume yet you do it to me. Irony has no limits eh?

I asked a simple question a long time ago, how is this different than say a non CO2 method? How is it different than say a low light tank with CO2?
Why might it work at low vs high light?
Will it work better at high light or low light?
Wouldn't adding activated carbon help remove some of the organic build up?
Can we get away with more with a different substrate?

I ask questions, and they will continue to come for many years.......
If some one asks me for help and says they want to do this and that is the only way they want to do it, I will work with them and see they understand the alternatives as well.

But ultimately, I help anyone that asks to try and solve their problem and help improve whatever method they intend to do. It's a process and folks work through it.

Stay focused on the plants, not the personal issues.

Tom Barr
See less See more
Jackfrost said:
Water changes ?

I am not convinced they are all together needed.

The only reason that Tom Barr method requires them, is because he takes the probabilistic approach that "if one throws enough arrows at a target, one will hit bullseye."
Jack et al, that is precisely my dang point. That target is huge.
Everyone use to say it was small, I showed otherwise and explored that.
Non CO2 methods are super, they require no water changes...............

As you increase light and CO2, the uptake rates increase, it's no ecosystem, it's a production farm.

I've tried to show the extremes with high light/VCO2 and non CO2.

Each method can be balanced.
You can do this a number of ways.

But folks have it all wrong about needing some water changes in a so called PPS tank.....isn't a non CO2 tank the ideal method for PPS?

No one has answered this even though I've asked it many times.

It provides the best results to this method and you don;t need to test nor dose much beside water, and fish food.

How lazy do you want to be?

You can go the entirely different direction and do lots of water changes, there's no rule a good aquarist cannot eye ball and do 50% 2x a month or even monthly, depends on what you are willing to accept as a result.

I have not clean glass for 6 months or more, they are clean, so is that better?

You can achieve balance a number of ways, but the underlying principles are still the same and have been done for decades.
The Tom Barr Approach:
Dump enough chemical nutrients (in some ratios) in the tank and hope for the best. The plants will take up what the need. If anything is left over, no worries. We will change 50% of the water and start all over again.
Is this a bad method ? Nope !. It actually is a pretty good method.

Is it bullet proof ? Nope !. You dump chemicals in a tank with no refference of its current state. You depend on the water changes to make everything reset.
Nothing is bullet proof but it's better than anything else when comes to setting up a certain range of nutrients(if that is your goal, you eesentailly make a know standard to within a certain degree of accuracy---see the water chnage dilution math if you have any doubts........).
Current state is irrelevant because the range of nutrients and their ratios that supply good plant growth ARE wide, so the target is huge.
Same applies to non CO2 tanks.

So your arguement about the current state being meaningful is really not that meaningful.

I've tried this and tried to see if it held true, I've gone to some very wide ranges. Unless you have foul wastewater to do water changes, 2ppm Cu, As, or water that is simply unfit for potable sources, then it's unlikely.

What types of reference states will not be reduced by 50% water changes weekly down to a low level?

High fish loads are about the only I know of or blatent mistakes.

I think the PPS method also has merits. I like the approach.
Would I eliminate water changes ?
Probably not. I would be highly satisfied with a lesser % water change than Toms method, where a 50% change is practically required every week.
I think I will try a modified version of the PPS, and drop my water changes to 25 to 30%. Observe the results and adjust accordingly.
Many do this, is it really a method?
Test and add what's been used up?
I don't think so.

[/quote]Be open to new ideas folks. No one has the correct answer here. This is Chaos theory at its finest. We are trying to bring equilibrium to a dynamic system. Impossible to do under the best conditions. The laws of science are against us.[/QUOTE]

Well, you can build assumptions into any model, but this not a new idea.
What is the goal, less water changes?
Well then a non CO2 method would be a better approach.

You can mix these together various ways, that's mainly all I see going on here. I've done this method for many years and many others.

That's how I got an idea on uptake rates at various lighting values.
Then using that could suggest a dosing rate that would satify all plants and all light levels and not cause algae.

You can slow this "method so called PPS" down or up by adding more light, less, non CO2 and see for yourself.

Tom Barr
See less See more
cards said:
Regards all (and my apologies to all at the same time for making my first post this one)
Ya know, this will be be short and sweet, you did what the rest of the folks have done, personalize it instead of answer the _dang questions_ I've asked.

1.I asked what is the primary goal of PPS?

2. How is it different than say what folks often do when they get lazy and don't do their water changes?

3. What is new that's been brought to to table here?

4. How is this better/different than a non CO2 tank or an excel dosed tank?

5. Is testing water quality why folks get into this hobby? Or is it to grow plants?

6. What about mulm accumulation and detritus?

7. Wouldn't watching the plants be better than test kits for things like NO3, algae for PO4, some plants for traces?

8. Are water changes really tough?

9 Can this be done with Discus? Heavy feedings? Why? Why not?

10. Light levels?

From what I can gather from evasive responses that go after me personally rather than the questions about the mechanism or plants, PPS seems to be a method of micro managing the tank and requires daily dosing/testing to avoid a few water changes till things get to out of whack. Then a reset. Folks did this for years with limited success. I asked how is this different. Again no response just pathetic whining about Tom Barr. I have ideas about this and other things that will help folks consider what they do and how they approach things. Doesn't matter what method you chose. Each has trade offs.

This has nothing to do with personal stuff other than a lack of response to the issue. If this is the cat's meow, I'd support it 100%, but ...I ask questions.

Why attack me and evade the other questions? That often means you lack support of your argument/s.So Again, I'll repeat these questions till I get a response.

No answer is an answer.
This is your first post and it's about complaining about something personal and not related to the plants..........

You can me flame all day, I'll keep asking the questions that are about plants.

Tom Barr
See less See more
Edward said:
Hi Tom
There is several.
First is to limit the Water Changes.
Believe it or not, there are people who do not enjoy it. So many people all over the world told you so.
I never said they enjoyed it. I said it could be made much easier. I also never said EI or any method must have weekly 50% water changes.
Many folks do it once every 2-3-4 weeks. Some do 2x a week at 30%.
50% weekly is just an easy to say middle ground that works for many with issues and allows them to re set their tank.
Plants and a tank does better with more frequent water changes, but it's certainly not required. As the frequencies of WC's decreases, so do the dosing rates. I would not add lots of KNO3 to a tank without also flushing it over a long peroid.

Second is time. No one can change water as fast as you can and you can not test as fast as many people can.
Actually I can smoke anyone on the list at testing, I have very nice testing equipment, I also have accuracy that exceeds anyone's equipment unless you work at a water quality labs, which, we have at the lab.
I use a NO3 test that uses a spectrophotometer. It's quite accurate(to about 0.1-0.05ppm NO3).
Most NO3 test kits take 5 minutes for resolution.
This is not an issue of speed of the user, that's the nature of reduction in the case of NO3.

Water change speed: I'm fast, I use larger diameter hoses and suck it out fast and refill. I also have set up plumbed systems that only require a quick turn of two valves to drain and fill. And then there's the automatic water changers for folks.................
I also have 14 tanks a several accounts. So if I do not do something about that, I'll spend a lot of work monkeying around.

Many of the tanks are non CO2, so in a sense, they are PPS.

Third is a comprehensive fertilizing system. This can not be said about the EI. The EI lack essential plant nutrients. Potassium is there only thanks to KNO3 overdose. Magnesium is absent, relying on accidental tap supply. The next is Calcium, another reason people in some areas could not be satisfied with the incomplete fertilizer.
Actually K is in sufficient amounts with out any KNO3 overdose.
If you consider the K and N ratios as far as plants, K is in excess at 4:1 ratios to N.

You are incorrect there in most all cases. Unless over 75% of the N is coming from fish waste, K+ is always in excess when using KNO3. Even then, I have suggested many many times that folks can use K2SO4.

The exception is with non CO2 tanks and with some low light/CO2 tanks with high bioloads.

But I've suggested some changes to non CO2 tanks to address this and the results are stunning.

Mg and Ca can easily, as well K+ be added and that is also suggested to maintain a GH of at least 3 degree and more is considered better. I've said that a few thousand times. If you do not do water changes for extended peroids, then you will need to add these. SeaChem EQ adds all 3, so adding it once a week solves that. MgSO4 is often added as a back up in small amounts if needed or CaCl2.
I generally will suggest folks add both or SeaChem EQ since few test kits available to hobbyists test for Ca and Mg individually if these seem potentially low. Doesn't hurt to add more GH anyway.
SC EQ is good for non CO2 tanks since one does not need to dose Fe/Mn either. But adding it does not hurt either..........

Confidence that nothing becomes deficient.
That's a good goal.
The question remains as to what else you are not able to test for that could causes issues...........
Many of those could be removed via activated carbon.

Simply running a canister full once a week or once every 2-3-4 weeks etc for 12-24 hours may really help in some cases to remove any organics you cannot test for.

"Vacuuming and filtration is not prohibited."
Neither are water changes:)
How do you vacuum and not do a water change?(there are few ways)

"Not many have the crystal ball."
Well many folks do know what plants respond to different nutrients because many folks have done the method and tried to add what the plants use up over the years. That would avoid more testing and plants don't lie.

I mentioned Mic umbrosum as an excellent NO3 indicator, Riccia for CO2, specific algae for other problems, Crypt "sheen" for traces, holes for K+, veining for Mg, and so on............
It's good to learn through experience as long as it's not your own.

That's where folks can help new folks.
This is much of reason I've asked specific questions.

You don't want me to look for your own post about someone running a discus tank without water changes for 2 years. There are people running successfully the PPS with discus under MH. Certainly, there are limits how much waste can plants consume, laws of balance.
And that law applies to all tanks.
Outputs = inputs
I doubt few would suggest that the Discus nor the plants would do as well as say a tank that got 2x 30% weekly water changes or a weekly 50% water change.

There are trade offs for not doing the water changes. What those are and methods to improve them were the orginal intent of this thread and folks precieved my comments as personal attacks.

Maybe you need to read the articles to understand the regulation principles.
I think I understand plant regulation quite well:)

Requires daily dosing? Yes it does, just like EI does and commercial products do.
Err no it does not.
Using your own words:
"Maybe you need to read the articles to understand the regulation principles.

EI can be used dosing once a week in low light tank(say 1.5w/gal), the dosing amount does not change, the frequency does as the light increases, this takes into account the rate.
I've said this a thousand times as well.

I'd also counter that PPS does not require daily dosing either...........
A lot depends on the light level/use of CO2.
In some cases monthly or none at all.

I think what it can really help achieve is a marked improvement with respect to non CO2 tanks...........

Many cannot grow many species of plants.........
Why not?

Many non CO2 tanks folks just live with the issue of some plants not being recommended, or not being able to make it.

I know this can and has been improved.
I would suggest folks to try PPS on a non CO2 to see this effect for themselves.

Many non CO2 do not test to see what is going on and have assumed many things about algae. That is part of the method that is suggested, no need to do the testing but the trade off is some species are very hard to grow, I think you can do either PPS or get a green thumb and an eye and some indicator plants and do it without test kits.

Now there's a supportable "option" instead of a personal attack.

I can ensure you there is no reason to do testing more often then once a week or less. This weekly testing is only for the start. Once the system is running, testing once after 4 weeks is adequate.
Now that sounds good/better.
Try it on a non CO2 tank. I think many will be quite surprised.
I did, I did not call it PPS, but that is essentially what I did and my goal was avoidance of water changes altogether and still be able to grow hairgrass and Gloss in a non CO2 tank. I achieved that. I also found I did not need to test much by watching a few species of plants. Plants never lie, test kits often do. One thing I do like is the focus on calibration of the test kits. Very good.

Thanks for answering.

Tom Barr
See less See more
Jason Baliban said:
*wipes sweat from brow* Phew now that was a long thread!!! After all that reading....can we just talk about the differences between the two methods. Please correct me if i am wrong, both of these methods use the same ferts in about the same ratio to one another? It seems to me that the only diff is how often and how much you dose. Am I missing something. Asside from routine of doesing what is the difference?
Originally that was the intent.

I see the methods as extremely similar as much as we might want to split hairs.

Both assume that algae are not limited by nutrients and that enough nutrients are added to support plant growth at a given light level, whatever that level of light intensity might be. Those are the several massive changes we have seen from other methods of the past including reef methods, non CO2 methods describe by Diana Walstad. Another is the test kit inaccuracies and the use of standards. That caused a great deal of confusion in the hobby. PPS would be plagued by issues here if this was not addressed since it relies on test kits. Traces and testing those are still an issue, although I'd argue a minor one for PPS. I eyeball that as does everyone for the most part.

If I'm going to eyeball that, I can eyeball other larger % nutrients in terms of plant health.

While testing is great and useful, especially to get a feel for some more advanced approaches, an aquarist can certainly move beyond test kits altogather with PPS over long peroids with most plants as they become more experienced.

One uses water changes and the other uses test kits to provide a stable environment for plants, but there are cross overs here and mixing between these methods, neither is exclusively a pure method.

I asked many questions to get people to think about these things.
A non CO2 method can be done in the method described by DW, Edward or myself effectively.

Plants can be used as your "test kits", fewer or greater water changes, % changed can be done, dolomite can be used, good test kits can be used, activated carbon, less light and it's influences.

I still find doing weekly water changes makes a tank look better than not doing them.

In giving advice to folks with algae issues, plant problems, PPS is tough sell due to all the testing and chem and requires more understanding for the user than say EI(Often it's a tough sell no matter how I suggest it as soon as you say KNO3.......), but non CO2 methods have both of those methods beat if fish food and tops offs are all you want to do, but you give up nicer growth and better results somewhat in doing that.

But to an experience person willing to test seeking a balance to their farm without water changes or a reduce number of them, sure, then it's a good sell. But I am thinking much further ahead than many assumed.........using the plants as your test kits as you become more familar with the dosing and push pull of the dosing routines is what I am hinting at.
I know that many folks after a number of years are able to do this effectively.
Edward seemed to scoff at the viability of this does work.

I know better........I use those kits to gain knowledge so I do not need the test kits forever.

In that sense, it's evolved further than PPS and requires more experience and knowledge.....also a tough sell......but PPS is a good path for folks seeking a more advanced approach to the nutrients pull/push effects or simply bored or have mastered EI or non CO2 methods. But like a water change, you can fall back on the test kits or water changes.

You can test and do all this with a non CO2 tank as well.
I did this the last couple of years off and on on the 4 gal cubes I had.
I also had a very nice tank in SB in 2002 with a nice field of hairgrass in a non CO2 tank. I think I can do it without test kits also (No water changes and dosing).

I found the higher the light, the more issues I ran into doing that.
The same can be said of any method IME.

Tom Barr
See less See more
1 - 14 of 49 Posts
Not open for further replies.