Don135

I hope this sub forum is still active, the last post I see was a few weeks ago. Maybe it's indicative of how well this system works . I do have two hopefully easy questions:

I have all of the necessary ingredients except for Calcium Sulfate (CaS04) which is called out in the Discus Mix. I do have Calcium Carbonate (CaCO3) and would like to know if I could substitute it for the CaSO4 and if so would it be at the same proportions (3 gr. in the solution). Moles and atomic weights were not my strong side in chemistry back in the early 19xx's.

Also from what I gather it doesn't matter what the plant load, light intensity, CO2 method, etc., is because of the "regulation loop(s)" and it's adaptability to each individual system, as long as I maintain the target parameters. If so I don't have to ask what my target variables would be based on my specific environment. Is that a pretty good summary understanding and I can start my dosing routine?

Thanks for the help.. Don

Don135

Ok I found the fertilator (great tool BTW). Trying to answer my own question I used the 3 gram dose in the Discus mix to an arbitrary 20 gal reference and came up with the following CA ppm's. I have both CaCO3 and CaCL2.

3 Grams of CaSO4 = 10.94 ppm

2.07 Grams of CaCO3 = 10.95 ppm
2.3 Grams of CaCL2 = 10.97

Based on this info I think I should (??) be able to use either CACO3 or CaCL2 in the above quantities. Is this correct, anybody?

Thanks Don

plantbrain

Don, while you should use the fertiliator etc to estimate the dosing followed by testing(namely N and P, but also Ca/Mg), one of the biggest errors with this, or any method for that matter is the CO2.

Good CO2 is critical and makes any method that much more robust and easy to deal with. Most of the failures with the method are related to this, but this is also true for eI, and most other methods that are commonly used.

The other issues: not enough plant biomass to start off with.
Don't be cheap and assume the plants will grow in.

Farmers do not do this with crops, they pack that field to avoid the weeds, so do the same to avoid algae.

Once the tank is well established, things will much smoother for you.
CO2 testing is wrought with issues for many and 40%+ of the plant's dry weight relies on this one nutrient.

So it's critical.
So don't get lost worrying about the relatively smaller nutrients that make up plants and neglect this one.

This will go a very long way to solving most any issue you may have when using this method.

Most that gave up, had issues with this one parameter, not the method of dosing itself.
The other issue is do not assume the other folk's suggestions for the test kits are correct, make sure the test kits YOU have are correct.

It's a lot to bite off initially, but once you start doing the routine, it's not that bad.

Regards,
Tom Barr

Don135

Well thank you Tom. Please don't miss-understand my feeble attempt to summarize the dosing regime. I was not trying to minimize the importance of CO2, Bio-mass, lighting, etc. I am just starting a planted tank and was trying to be succinct for everyone and prevent one from having to read a thesis on every little detail of my tank, plants, etc. and ask how many ml of each nutrient/chemical I have to dose and when. The PPS regime and process appears to be adaptable to a multitude of systems and the variable uptake of nutrients of each system by maintaining a fixed ratio of specific nutrients in solution, and dosing to maintain specific target levels of others. That's my current understanding. I'm not a chemistry guru and wanted to validate that I could substitue a Ca source in the Discus recipe. After finding the Fertilator I believe I can.

Regarding CO2, I am going pressurized with a pH controller eventually. I hope to be ordering one sometime this week if I can piece something together and make a decision, never enough time. In the interim I'm using Flourish Excel to supplement.

Don't worry I'm not being "cheap". After spending a considerable amount on filtration, lighting, and substrate upgrades, new test kits, RO cartridges, plumbing retrofits, etc., etc., a few more plants isn't going to "break the bank" per se... I put 4 more "bunches" of plants in yesterday and could probably use more.

And I've also started the tedious test kit validation processes mentioned in this system for my new kits. The Fertilator is being a big help here. That's as much fun as watching my Anubias grow..

Thanks again, Don

plantbrain

Yes, but 90% of folk's issues tend to be relatable to something other than PPS's routine, same with EI. The advice merely helps anyone using CO2 etc avoid algae and makes full use of any method.

We also did the ratio thing back many years ago(mid 1990's), since, many have moved beyond test kits. Nothing wrong with them though as long as they are accurate since you base the dosing on their readings, that introduces another set of things you need to test, but they can be tested and then you use them and monitor.
Some say you can test them once and then from then till the end of time they will all be the same, no, this is simply not the case. Frequent calibration is useful, do not toss the standards away.

Ratios really have no bearing in any and everything I've seen in planted tanks, argiculture and in the natural environment.

I've found no support from that in wetland science, aquatic botany, terrestrial agriculture crop science etc. Pretty wide range I'd say.
Mainly an issue of providing non limiting conditions rather than a defined ratio. Simply maintaining a stable range for each nutrient is a good goal. You can dose and not do water change and test, you can do water changes and dose.

If you or anyone has evidence to the contrary that ratios are important, I'm all ears.

Make sure to measure the KH often if you do not do water changes for extended time frames.
You may find you need to more CO2 than the reading might suggest. So some serious tweaking may be needed.

So it's questionable to focus so much on testing PO4 when the CO2 measurement is far off. Often by 10ppm and often much more.

Check some of the post about folk's CO2 ppm numbers they have without dead fish. They go from 20-120ppm of CO2.
Those are calibrated pH test kits, but many do not calibrate their KH test kits..........

Well, in some circles, that is a compliment!
Cheap+ simple but effective is a good goal.


Well, perhaps you see why I evolved away from test kits.
Some find it tedious, some like it. We did the same thing in the mid 1990's but with water changes. A number tried it without water changes, seeing how long they could go. Dave went 2 years. Steve 6 months, I've gone 4 or so. I used Lamott and Hach test kits as did several others.

We did not use an excel spread sheet etc as part of a routine, but we did maintain the nutrient levels within a "range" which makes more sense than "ratios" in terms of genetic enzyme signaling within the plant, basically tells the plant the levels are stable so the plant maximizes the enyzmes available for uptake and allows better growth. Ag research supports this.

But back to the issue, Ca can come from CaSO4, CaCl2 etc. As long as you add enough within a range, you'll be fine. PPS has a range there also. Not just a ratio. A stable range is a better notion than a sable ratio.
I can grow plant fine at 20ppm NO3 and 2ppm of PO4 the same as 30ppm NO3 and 1.0 ppm PO4. Ratios are different but the range is relatively the same.

Just look at the CO2 carefully before you think things are problem with the dosing in PPS. It's much less of an issue for Excel users with lower light. When you add CO2 gas, things will change.


Regards,
Tom Barr

Edward

Hi
The CaCO3 will not work for most plants and it is also very alkaline (high KH). Why do you need the Discus Mix? Are you using RO?

Don135

Hi Edward,

Yep, 100% RO... Liquid rock here and have a long history (15 years) of issues with trying to blend my well water with RO. Periodic fish deaths, intermittent diatom and algae blooms, etc., etc. 100% Reconstituted RO is the only thing that eliminated these issues over the years. These were fish only tanks, and now my first planted tank....

Back to the CaCO3, I tried it once couldn't get it to dissolve, etc. and have since used CaCL2 exclusively to restore my Ca.

Don

plantbrain

Well water change have a fair amount of variation in some cases, and stable as can be in others.

Running it through a pre carbon filter can help.
You can make a standard reconsitution using baking soda(KH of 2 or so is good) and CaCl2/MgSO4 or CaSO4 in place of CaCl2 if you chose.

Make sure this is well mixed prior to adding to the tank.
CaCO3 can be used in some cases, but as you have found, it takes a long time to dissolve.

The tank should balance pretty well and keep up on the CO2. It's critical in PPS and is the largest single variable in test methods. So keep things in good shape testing the Ca/NO3/PO4 etc, but really keep good tabs on the CO2.

CO2 is the most challenging thing.

Regards,
Tom Barr

bonklers

Hi,

I've been looking through the PPS article, I see only what the discus mix contains but I can't find any information about how to dose it. Like in: how much of the dry Discus mix should I add for 75 gallon, and at what frequency when I do a weekly WC?

Edward

Hi bonklers
The point is to maintain around 20-30 ppm Ca. Most water sources and substrates supply enough Ca. If you use RO then you need to add it. Try two teaspoons and then test for Ca the next day. Once you reach the desired level then dosing is not necessary for several weeks.


Thank you
Edward