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Discussion Starter · #1 ·
Hi everyone!

So I'm a little stumped and I could use some opinions from everyone here. I'm having a problem with a couple plants worst with my my Nesaea pedicellata 'Golden' and less so but still present in my Alternanthera reineckii. A few other plants are showing mild symptoms of mystery deficiency but I'm assuming the higher demanding plants show it worst.

All plants seem to be stunted/slow in growth. Smaller leaf growth on most and on the two plants previously mentioned deformation in new leaves/tiny. My Bacopa leaves seem to also have a downward curl sometimes to the extreme of making a tube shape!

Tank nutrient specs are as follows:

Heavily planted 75 gallon with T5 HO lighting sporting about 250watts of light.
CO2 injection with a Ph meter regulator
Ecocomplete substrate

Temp : 75F
ph : 6.68-6.79
CaCO3 : 90ppm / 5Kh
Ca : 60-80ppm
Mg : 20-25ppm
No3 : 8-12 ppm
K : 12-20ppm
PO4 : .7-1.2 ppm
Iron : trying to maintain .1 ppm with flourish iron
Trace : dosing 5ml 3/wk with flourish trace

I have a Hanna 83200 bench photometer so I would say minimal error in measurements. No matching up the color here [smilie=n: I feel like considering this advantage I must be missing something fairly obvious and simple!

My thoughts are maybe not enough trace/iron? Maybe I need to go chelated iron? Any thoughts are appreciated. Especially from you pros. Please if I missed any info you think might help ask away!!!
 

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Hmm, well ordinarily I'd jump to saying a calcium or magnesium problem, because new leaf curling is a classic sign of calcium problems. Furthermore you can get calcium deficiency problems by having an overdose of Mg since the excess Mg interferes with Ca absorption resulting in a Ca deficiency. Without pictures its hard to say.

How are you testing these values? How sure are you that they are accurate? Have you calibrated your test kits?

Other things that might cause leaf curling is if a lot of salt (Na+) got in the tank (sodium will also strongly interfere with Ca/Mg/K uptake). Sources are commonly from a home water softening system or from treating fish for diseases with salt.

It might also be a boron deficiency though this chance is pretty remote since you are using a brand name micro fertilizer, the interesting thing is that you mention the leaves curling downwards making a tube. This is not really characteristic of Ca/Mg deficiencies but of boron problems. I've attached a picture of my R. macrandra when it had a boron deficiency.

Post pictures for us it will make things easier. And redo the water tests if you can for Ca/Mg. When did these changes start and did anything different happen before the problems started? How old is this setup?

 

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Discussion Starter · #3 ·
Here are some pictures I took from my phone hopefully they came out alright.

The Hanna HI83200 Photometer is really accurate.

If it is boron what is the goal level (ppm)?
 

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Are you measuring all your nutrient levels? If so, how? It looks more like iron deficiency than anything else. Try to get your iron up to 0.3 to 0.4 ppm and see what happens. Don't increase any of your other micronutrients.
 

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Discussion Starter · #5 ·
Are you measuring all your nutrient levels? If so, how? It looks more like iron deficiency than anything else. Try to get your iron up to 0.3 to 0.4 ppm and see what happens. Don't increase any of your other micronutrients.
Yes, I measure them all about once a week to keep them in the ranges. See above about how I'm measuring. I've gotten it down so I know exactly what I need to add most of the time and confirm it by testing when I need too. Use of most nutrients has slowed at this point because of something lacking or wrong.

I'm thinking you might be right with iron being part of it. I'm having trouble keeping the flourish iron levels up in a good range. I think I need to get something that is dpta chelated so it stays usable longer. Does anyone know a good place to get that??
 

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Discussion Starter · #7 ·
Im going to say CO2 is what is missing. How do you measure it? When is the last time you calibrated your monitor?
I calibrate/clean it weekly with every water change. I will say in the past I wasn't so diligent which gave me issues. But it seems to drift upward meaning it will read a higher PH than is actually present. If it does(it did) swing far enough that the actual ph is near 6.5 would that effect the plants this drastically?? I did have that issue not too long ago. It has been corrected for the past month by calibrating weekly. Do I need to wait longer if the plants are recovering?? The snail shells in the tank aren't so swift looking after the issues I had......hmmm. Maybe I need to replace the probe?

Do you have issues with yours often???

I use the typical dkh to ph chart to calculate it.
 

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Discussion Starter · #9 ·
I havent ever used one as I never heard of one being reliable. Its just 1 more thing that can mess you up IMO. There are way to many things that can buffer your water leading to false PH readings. Measuring CO2 via PH and KH is not reliable in the least.
What is IMO? Sorry new to the forum and the acronyms.

What buffers would I no be aware of?? I've read anything beyond CaCO3 is minimal in freshwater and not worth worrying about, not true? I also have extremely soft tap water as I have to add most nutrient to my water. I add CaCO3 to buffer which also helps me get my calcium where it needs to be. If I'm getting a false PH reading that would surely explain things but what would cause this? I have done the regular API PH color comparision test to compare to my meter when I have doubts, and it has always confirmed it accurate. Would it throw both off?

I will say I have used the PH and dKH chart for the past year and it has always seemed to be pretty accurate for me(as long as my PH and dKH measurements have been accurate). By accurate I mean my plants have grown very well and I noticed pushing beyond the 30ppm mark, where the chart claimed it to be, caused some distress with a few fish.

I know there is a lot of bad press and bias about those charts out there. I personally find it hard to find fault with a scientific chart. I believe the traditional color match and number of drops testing has too wide a margin of error measuring KH and PH to use this chart. All it takes is being .1 PH off and a degree off your KH and you have a massive lack of CO2 or overdose. I'm guessing that was your point, which I fully agree with.

Anyway, back to my main question, what buffers might be throwing things off? But if I had more mystery buffers wouldnt that mean my actual CO2 is higher than the chart would claim rather than lower? Wouldn't that dissprove the mystery buffer theory?

Just thoughts to chew on, not trying to step on anyones toes.......:-k
 

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IMO = in my opinion

For general background purposes:
There are many different types of buffers and for that matter many types of acids that are present in your aquarium. For the pH - KH relationship to be true all your acid must come from CO2.

For example, if you had adequate CO2 levels in the tank but then you added a non-CO2 acid to the tank your pH would drop, and according to the pH-KH relationship you would have way too much CO2. This is wrong. In the same way if you had adequate CO2 and you added a non HCO3- (bicarbonate) buffer your pH would sky rocket even though the actual CO2 levels are correct. The pH-KH relationship would incorrectly tell you that your CO2 levels are too low.

In the tank there are many many types of acids, for example, amino acids (from decaying food/plants/bacteria), H2SO4 (from bacteria), HCl, H2PO4 (from cells), organic acids, keto-acids, NH4+ etc... These are all found in varying levels in our aquarium and there is really no way to accurately measure these and seperate them from the acidity made by CO2. In the same way there are many non-HCO3 buffers (only HCO3 is included in KH) that could be in the water, some of which are NH3 or HPO4.

The pH - KH chart is definitely inaccurate when measuring the actual CO2 concentration in our tanks. It can be used as a very general indication though. But we really have no way of knowing how wrong it is since everyone's tank has different concentrations of the above buffers/acids. At this point in time there really is no accurate way to measure CO2 in our aquariums, most of it is guess work.

That being said I don't think CO2 deficiency is very common. Even with no added CO2 the ambient level of CO2 in moving water is around 2-3 ppm CO2 compared with about 30 ppm when you are injecting CO2. I feel that if you are adding any CO2 at all to your tank (especially pressurized) you probably have more then 2-3 ppm which is enough to grow plants (albeit slowly).

But back to the nutrient problem:
Nesea can be a really finicky plant. It definitely likes micros. Whenever I grow this plant I always use soil to plant it in. When not using soil it tends to develop growth problems if your dosing slips up at all. The general yellowing of the entire plant seems to lend strength to iron deficiency (another nutrient that is difficult to measure with tests). However, I've never seen crinkled leaves with iron deficiency before, that really looks more like a Ca/Mg problem.

I think what you should do is start testing out our suggestions one at a time. Or all at the same time if you are more concerned about plant growth then an finding an exact cause.

1) Increase your micros, 2) dose iron at lights out time (since bright light tends to break down iron into less usable forms), 3) retest your Ca/Mg and fix that if needed, and 4) double check any possible sources of sodium in the tank (baking soda is NaHCO3), 5) check CO2 levels.
 

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Discussion Starter · #11 ·
I stand corrected! Thanks for the education. I hope no one holds my ignorance against me. I guess I will have to start rechecking some things to figure this out!
 
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