Aquatic Plant Forum banner
1 - 13 of 13 Posts

·
Banned
Joined
·
2,069 Posts
Edward, how high on the Mg?
I have some I saved from the SAE's, it's doing well, so of course I now want to torture it:)

Regards,
Tom Barr
 

·
Banned
Joined
·
2,069 Posts
Well, try it and see.

It's growing well for me, so I'll just add known amounts of Mg to the tank till I see a negative response.

Regards,
Tom Barr
 

·
Banned
Joined
·
2,069 Posts
Mg is more common for issues, many suggested it was K+, but CO2 and Mg will influence that more than Ca which tends to rarely an issue but an oft loved excuse for poor growth.

High levels of NH4+ and Mg++ will block K+ far more than K+ ever will.
And there is research to support that.

So do not go nuts with Mg.
You just need a little bit and the ratio itself is not going to cause much issue if the Ca is high. 10-20ppm is more than enough.

Regards,
Tom Barr
 

·
Banned
Joined
·
2,069 Posts
Edward said:
Hi All

The Rotala wallichii been growing well at 20 ppm Ca and 2 ppm Mg. However, it stops growing when Mg changes to 10 ppm. When conditions change back to 2 ppm Mg the plant starts growing again.
This test I have repeated several times. Please take in consideration that the Mg is from MgSO4, not MgCO3. The Ca is from CaSO4 and CaCl2, not CaCO3 nor CaNO3.

Thank you
Edward
I'll give this a whirl.
I like the Rotala and it does grow back fast when happy.
What might be interesting is focusing on the KH vs Mg.

I know many folks that have rather high GH's, many from dosing SeaChem Eq and in a number of cases they have Mg over 10ppm but an associated higher level of Ca as well.

Ca/K/Mg/NH4 blocking all appears to need to be much higher concentrations typically found in pore water to start to get blocking. But species to species difference may play a larger role.

I have found the Luwigia cuba to stunt much like the R wallichii in the hard KH/GH's, but teasing apart which is causing what requires more grow out and then changes to the Mg, KH and Ca levels.

In general, if there is a GH issue, lower Mg is typically the reason if the GH is already high, it's virtually unheard of to find high Mg and low or limiting Ca levels if the Gh is 3-5 degrees or high.

Many folks have high GH's and does well with Rotalas and Ludwigia cuba.
It might be evidence of a ratio being important even at low concentrations.

Regards,
Tom Barr
 

·
Banned
Joined
·
2,069 Posts
dennis said:
This may be true but it could be a dangerous way of thinking. This statment considers natural water sources. After my water supply went back to normal and I started adding 1/8tsp Seachem Equilibrium at wc, it has been growing gang busters. Probably for the last month or so.

I thought you always say ratio does not really matter as long as the Gh is over 3-4 ;) Just yankin your chain!
They don't, but your new routine adding a little bit of SeaChem Eq each week will address the issue(which is Mg limitation), we found this out about 10 years ago in the Bay area using this product.

Many thought it is was all the K+, which was all the rage back then.
Some thought it was the Ca, Steve Dixon wondered if it was the Mg. He's alos the guy that found out I had such high PO4.

He had so many things right on looking back, too bad he's not active any longer.

I'm about ready to torture some wallichii also. Bring on the salts!

Regards,
Tom Barr
 

·
Banned
Joined
·
2,069 Posts
Most salts will absorb water and become rock hard rapidly, that's why they add rice to absorb water vapor to salt shakers.

I'll do some measurements for the GH booster, dang, i hate it when my name gets attached to something:)

It's Greg's Creation inferred from something I wrote at one point.
It should have the same effect as SeaChem Eq if used the same although it has less K and more Mg if he used something I said.

You have weird tap, one of the few that has high Mg.
This is a good thing though, you can see what impact high Mg has on plants.

Edward's example did not look good:)
But you never know.

I've had all sorts of Ca levels and K levels etc, I suppose I can really max the Mg out, I've been meaning to anyway.
Done most of the others.

I've never found any evidence of a ratio based issue though with Ca/Mg/K to date in any research. As long as they are non limiting and not extremely high, they do not impact crop production. I typically look at rice studies since they are the huge ag crop that is also an aquatic plant.

Regards,
Tom Barr
 

·
Banned
Joined
·
2,069 Posts
There's no need to chelate Mg, but Mn is another matter.
Typically in traces, Mn as well as Zn, Cu, are chelated, EDTA.

Regards,
Tom Barr
 

·
Banned
Joined
·
2,069 Posts
JLudwig said:
Hi gang... there are two plants giving me similar issues, L. "Pantanal" and sometimes R. macrandra "green". The rotala surpises me a bit since it used to grow really well for me. What will happen is that occassionally, early week after a WC it would stunt, then later in the week would have nice growing shoot sent out already, but not as prounced as what Edward posted. I've tried a few things and seem to have it under control, at least with the rotala. I basically starting going to 1/2 RO 1/2 tap, and switched back to entirely TMG as a trace, 2ml/day per 10 gallons, 6 days a week. Rotala is now fine - now I'm working on the Pantanal.

I tried elevating both Mg and Ca in the proper ratios, that didn't help, also adding more Mg didn't help. So now I'm trying two weeks of elevated calcium, if I forget to update the thread please PM me and I'll post results. Everything else in the tank is growing fine so its a matter of getting some of these fussier plants to stay happy.

Jeff
Probably CO2 then.

Rotala's love it when it's high, a little drop off and you'll get stunting.

I think that is the main issue with many folk's stunting issues and certain species issues.

They see one thing and incorrectly attribute it to Mg or Ca.
I'll suggest adding most every nutrient to excess, that is relatuively easy to do.

From there all you do is tweak CO2.
This is the best method to get good growth for folks.

We can add known amounts of Ca/Mg/NO3/K/PO4/etc, then adding CO2 is all that is left.

We can gauge the max amounts that might be needed by other folk's parameters for the same plants.

From there, if those match up, CO2 is the only thing left.

I see too much confidence in folk's reports of CO2 levels and reports of very wide ranges of CO2 ppm readings for it NOT to be a huge issue.

I'd say many/most of the Ca/Mg issues are CO2 related.

Regards,
Tom Barr
 

·
Banned
Joined
·
2,069 Posts
dennis said:
OK chemistry people:

I just got a LaMotte Ca test today and 2 runnign 2 tests I get the same answer of 95ppm Ca, read as ppm Calcium Hardness as CaCO3.

In the following equation used to find the ppm of Mg, does the Ca in ppm number need to be converted from my reading of 95ppm as CaCO3? If so, I would divide by 7.143?

GH in ppm - (2.5*Ca in ppm)
--------------------------- = Mg in ppm
4.1

Any help is appreciated!
Your Ca is 95ppm x mol CaCO3/ mol Ca = 40.08+12+3x16/40.08 = 2.5
95/2.5= 38ppm Ca++

The above equation off hand appears right.

Say the GH (total hardness as CaCO3) is 120ppm.
120-95 = 25ppm Mg as CaCO3 equivalents.
25/4.1= ~6ppm Mg.

I'd not bother with this, knowing the difference between a few ppm in a ratio is not going to do much for you unless you desire to add very small, potentially limiting amounts.

Nothing I've found suggest a ratio of Ca/Mg does much, the amount of error in our testing and habits plays a much more significant role I would suggest.

Add a little of both Ca/Mg to your tank each week beyond the amount of plant growth requirements, say 10ppm of Ca++, and perhaps 4ppm of so of Mg++ and you are set. That's in addition to the Mg/Ca in your tap water, other sources.

Regards,
Tom Barr

PS-
I recently bumped my Mg up with Rotala wallichii, unlike Edward's photo's, it did not stunt. I am using soft water(KH = 2) and low GH's.

5.4 grams in 1 teaspoon of MgSO4*7H2O.
9.9% of it is Mg.
So per gram of Epsom salt added to one liter: 9.9/100= 99 ppm or mg/L.
So per gram added to a 75 liter(20 gal tank) 99ppm/75= 1.32 ppm Mg++.

5.4 x 1.32 ppm= ~7ppm of Mg.

I added 1.5 teaspoons, a fair amount of Mg to such a small tank.
10.5ppm and that does not include the fraction for the tap.
Generally 1/4 to 1/2 teaspoon per week will address any Mg issue.
But those with higher GH's, likely can use more if they want without issue.

I have not done enough with Mg to say much still.
I only did the Rolata test once. I waited for 3 days after.
So who knows just yet.

Still, adding the rec's I suggest are fairly light, not excessive, if you apply the EI notion to 2x the weekly build up if no Mg is used, then the amounts end up in the 2-6ppm range generally.

Folks have been using Mg in PMDD and with other mixes for a long time.
I tend to suggest a few degrees of GH for soft water, about 3-4 at least using SeaChem EQ or the Gh booster, folks with harder GH waters may need some Mg or Ca to balance things out so neither is limiting.

I think you can approach it that way, using just GH and adding a bit more with a balanced product or................you can analyze GH individually into the Ca and Mg sereprate nutrients.

I'd stick with one method though, that will simply things.
At the end of the day, I do not think you will see marked differences with either method.

Both can supply the required amounts of Mg and Ca.
One test more, the other uses a GH kit or none at all.

Simply because you do not test, does not mean you need to know what the ppm of Ca/Mg, only that you have enough to prevent limiting conditions.
That's the real issue for 99% of aquarist, not confusing themselves with test kits/methods.

Why test unless there is a problem?
How do you avoid such problems to begin with?

Pretty straight forward.
If you suspect K+ is limiting, then add more K+ and see.
You do not need to test the K+, you can if you want, but you do not need to do so to know the K+ is limiting or in excess. Simple calculators will tell you that.

Regards,
Tom Barr
 

·
Banned
Joined
·
2,069 Posts
JLudwig said:
Well I do think I can cross that one off, as I use a calibrated pinpoint probe, and don't measure KH. A sample of my tank water goes up 0.8-1.0 pH points with a few hours of vigorous aeration with an airpump, Ive found that to work pretty well. Other than upping the dose of calcium, I've backed off on my trace a bit, maybe its not a deficiency but a toxicity issue, whatever the problem it's (a) hard to reproduce and (b) only affects the fussiest of plants. Mg/Ca ratio is a good scapegoat, it will one day mysteriously get better, I'm sure of that. A "heisen-bug" if you will. And the whole exercise is a bit pathological as I would easily sub in one of the 300 other plants I can grow well :)

Jeff
One measurement or two in time means little, you need to keep track of the CO2 over the course of the treatment.
At least one full day of observation and then thereafter am/pm or if anything is funny looking.

It's nothing like NO3 at 20ppm.
In 30 minutes a tank's CO2 can drop fast.
Many things influence CO2.

The more I know, the more I doubt.
Uncertainty is high is all.
I've seen evidences of CO2 ppm changes throughout the day on many tanks.
I'm very leery of CO2.
I play with that much more than any single nutrient.

I can help with the toxicity issue.

I added 200mls to a 20 gallon tank of Flourish, not 20, but 200mls.
The water was very dark and stayed that way over the 3 day peroid.

No stunting, not shrimp issues, nothing relatable to toxicity was ever observed. I used TMG to dose to 2ppm of Fe a decade ago, I had very good plant growth.

Regards,
Tom Barr
 

·
Banned
Joined
·
2,069 Posts
dennis said:
Tom,

That's the first time I have ever seen you do math! Not that you don't do math, just never seen you type it all out. Now I feel special :)
Don't.
I scare folks with talk, add math and they really cringe.
I've posted plenty in the past that details out Chemistry.
There are links all over going pretty far back.

However, this does not explain the only .4-.5 pH drop the tank can handle.
Well, that right there explains a lot of your tank's issues, more than the Ca/Mg thing.

You can change this by adding more surface movement, a slight rippling is good, flake food should move around the surface but not be torrented under the water.

I think I may have to do some mucking with surface movement but anymore turbulance and I will get whitecaps!
Then white caps it is.
But........the testing method for pH............what are you using? Get a pH pen or monitor if you do not have one.
Most everyone can knock it down a full pH unit without issue.

I may try just adding some GH Booster or Equilibrium but I really wanted to pinpoint this, if for no other reason than personal satisfaction!
Well, careful of what you wanna know there.

Plus, the fact that only new growth and not old growth was affected pointed to immobile nutrient deficiency.
Low CO2 suddenly also causes the same expression, stunted smaller growth of the vegetative tips, is CO2 a mobile or non moblie nutrients?:)
This is a trick question.

a)faulty test readings
b)CO2 fluctuations/limitations Do you turn off the CO2 at night?
You can easily rule out the K+ if you use KNO3.
Traces: see previous post.
They are traces, while needed, they have a wide range, and the expression is very difficult to prove in isolated studies of what the stunting might look like. Measuring tiny tiny amounts is very difficult except in highly controlled studies.
Toxicity has never been show in aquariums with Flourish or TMG to my knowledge. I certainly have been unable to show it when dosing even 10x the normal high dosing amounts.

So focus more on a and b. That and the pH drop says a lot.
Don't worry, even the best get nailed with CO2.

BTW: here's why the K from KNO3 is unlikely to be an issue in terms of limitation:

http://www.aquariacentral.com/forums/showthread.php?t=21033

One poster had a common error, but it was caught and corrected.
Unless you have nearly 75% of the N coming from some other source, such as fish load or tap, it's very unlikely you need extra K from K2SO4.

Steve Dixton postulated both the K was enough from KNO3 alone and that adding Mg was more critical than we thought.

He said that to me back in 1997.

Regards,
Tom Barr
 

·
Banned
Joined
·
2,069 Posts
Zenfish:
That tank looks trace limited to me, switch to TMG since you have hard tap water. Add a tad more CO2. Not much, maybe .1pH unit further down.
You also need to add some more PO4/NO3.
Low nutrients and stressed plants.

Dennis, welcome to the real world of low CO2:) Somewhat humbling huh? If you have not been there, just wait a awhile, everyone that's been in the hobby long enoyugh goes down this road. Many still fight it and think their CO2 must be in good shape and thus chase funny nutrients issues around.

Look at plants more, distrust test kits=> they should have to prove to you that they are accurate and correct.

Elkmore, add good CO2, add more Traces, set things up to isolate the Mg or Ca, do this by providing non limiting conditions for the other nutrients.

You can see if the Mg is the issue by doing this and adding everything but Mg, wait about 2 weeks and you should see the signs of Mg limitations.

Then look very carefully at how the plants grow and which species are effects etc. This will give you a better cause/measurement approach than the guessing and chasing after each nutrients.

It's fairly easy and straight forward.
You can do this for any nutrient easily.

Regards,
Tom Barr
 

·
Banned
Joined
·
2,069 Posts
I have not seen any definitive patterns as of yet to that effect.
Some have suggested it goes away when they added more Mg.
Same has been said for Traces, NO3, CO2 etc.

Few seem willing to trash their tanks/plants in a controlled manner to answer such questions. Those with ther ability to do that, don't have the curly leaf issue to begin with and have the control, those with curly leaf, often do not have the control the begin with(ability to confidently rule out another possible confounding cause).

Later this summer I'll have time to set and few things up for Mg.


Regards,
Tom Barr
 
1 - 13 of 13 Posts
Top