# [Wet Thumb Forum]-What is inhibiting Ca uptake?



## geoffrey (Jun 15, 2004)

Hi All,

Lately my L. cardinalis are shooting out very small leaves with white streaks on them; the leaves of my H. corymbosa are cupped downwards and distorted; and E. orientalâs new shoot is almost white in colour. This is Ca deficiency, right?

But I have a load of coral chips in my filter sump and I doubt they are not providing enough Ca for the plants. My kH is 7, pH is ~6.5 and I suspect my gH is above 10 although I have not measured. Could there be something that is inhibiting the uptake of Ca?

My tank is ~100Litre. It is heavily planted and has a high fish-load. I use PMDD and dose twice weekly for a total of approximately:
NO3 = 25ppm
PO4 = 0.5ppm
K= 40~50ppm
Mg= 5ppm
T/E = to a level where Fe shows 0.5ppm

My tank was doing well after BBA. What could be inhibiting? Could it be my high K? Please advise.

Geoffrey


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## geoffrey (Jun 15, 2004)

Hi All,

Lately my L. cardinalis are shooting out very small leaves with white streaks on them; the leaves of my H. corymbosa are cupped downwards and distorted; and E. orientalâs new shoot is almost white in colour. This is Ca deficiency, right?

But I have a load of coral chips in my filter sump and I doubt they are not providing enough Ca for the plants. My kH is 7, pH is ~6.5 and I suspect my gH is above 10 although I have not measured. Could there be something that is inhibiting the uptake of Ca?

My tank is ~100Litre. It is heavily planted and has a high fish-load. I use PMDD and dose twice weekly for a total of approximately:
NO3 = 25ppm
PO4 = 0.5ppm
K= 40~50ppm
Mg= 5ppm
T/E = to a level where Fe shows 0.5ppm

My tank was doing well after BBA. What could be inhibiting? Could it be my high K? Please advise.

Geoffrey


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## Rex Grigg (Jan 22, 2004)

Your potassium levels are way too high. High levels of potassium will cause calcium uptake problems. You should run the potassium no higher than around 20 ppm. Even at this level I have found some plants will start to show small signs of calcium deficiency.

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## geoffrey (Jun 15, 2004)

Thanks Rex. Will reduce K from now on.

Geoffrey


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## JamesHoftiezer (Feb 2, 2003)

I can second Rex. At one point we beleived you could just keep adding K with no side effects, but inthe last 3-4 months we've started to change our opinions. 
I think we've realized that an excess will cause interference with ca uptake. I dose only enough to keep my plants pearling.

*James Hoftiezer

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## imported_Svennovitch (Feb 1, 2003)

James,

i thought you were adding 5ppm of K every day? Am i right? That is about 35ppm a week with low water changes. Can you explain why you don't seem to have issues with overdosing K?


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## JamesHoftiezer (Feb 2, 2003)

I've been cutting back on the K and recently have been doing more significant water changes (contest







). At 35ppm I may have been having issues, I'm just too newbie to really diagnose it.

I dose based on visuals. If the tank is pearling and happy I'll skip a day, so I wasn't always dosing everyday. Its the recent discussions that have me second guessing how good some plants have been doing. With Ca up, I'm wondering why some seem to be showing symptoms of deficient Ca (i.e Rotala Indica is bending over).

On that same idea, is the K being consumed? Is is possible that my tank is going through 20-35ppm of K each week? Any ideas? Have I built it up to what might be a very high level, but still no toxic effects?

I honestly don't know. That's why I'm tossing things into the discussion here.

*James Hoftiezer

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## Roger Miller (Jun 19, 2004)

> quote:
> 
> ...is the K being consumed? Is is possible that my tank is going through 20-35ppm of K each week?


James,

I posted a fairly convoluted letter in the main forum to the "Potassium and Test Kits?" thread. It has some relevant information.

In order for your plants to consume 20-35 ppm of K each week they would have to consume about three times that much nitrate. Do they consume 60-105 ppm of NO3 each week?

If they aren't, then the potassium was (is?) building up in the tank to some point where it will be controlled by water changes. You can probably go through the calculations I did in that other thread to estimate about where the potassium level in your tank might be.

There is a disclaimer about accuracy at the end of that letter. It's a good point to keep in mind.

Roger Miller


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## imported_Svennovitch (Feb 1, 2003)

Do you think the bending of rotala rotundifolia is being caused by Calcium deficiency? Interesting. I always assumed that it was the potassium, but never thought about Ca deficiency.

The bending of RR started immediately after i dosed K for the first time. I had the same observations with Hemianthus micranthemoides and Heteranthera zosterifolia.
About three to four months ago, suddenly the plant tips distorted, without changing my dosing routines. I didn't think of any Ca deficiency because i knew my tank has enough of it (my tap water has 127 mg/l, thank god it rains a lot over here







so i am using rain water). My first reaction was i am overdosing something, time to change my own PMDD formulae. Since then i switched between underdosing and overdosing... because i am using an Eheim Liquidoser, i add every day the same amount of fertilizer. I hope one day i will find the right concentrations for my tank









Birgit used TMG for her tank, and she had never any issues of deficiencies (macros or micros). She had a high fish load but that doesn't help for the potassium. TMG has a lot less K than we dose. And if i look at the pictures of RR in the plant database, then i just know RR doesn't need as much K as we are dosing...
When she switched over from TMG to DIY fertilizers, she noticed the bend-growth as well.

Regards,
Sven


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## JamesHoftiezer (Feb 2, 2003)

I started into this issue from the opposite direction. I was already dosing high K. I had excellent growth pearling. Then I started dosing higher traces than normal. My trace mix has my Mg in it propotional to the PMDD mix. Along with the higher traces/Mg I noticed the rotala indica stunting and growing to the side.

When dosing I have only been adding a few ppm of nitrate weekly. The factor I can't account for is the nitrate from the fish load. I have ~140" of fish in a 100g tank. By regular aquarium standards that is a heavy load.

With the contest over, let me run out the ferts I have in there, do some water changes and starta good journal. Right now even my anecdotal is not very accurate and my questions are little more than fishing expeditions. My tank speaks for itself, but I'm not sure what its saying yet. This tank and its owner are only five months old and we both need to mature some in this science.

Now that I've pulled back the Mg in the trace mixture the rotala.indica has picked up its growth and has stopped the side growth, but it is barely anecdotal given the irregular dosing during contest picture week.

*James Hoftiezer

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## Guest (Apr 30, 2003)

For the record,
I have never seen any Ca deficiency in many years of having high levels of K, 40-60ppm range for a sometimne with many species of plants. My GH levels and Ca levels have run from 3 to 25 and 30ppm to 440ppm+.

I suppose if you really took things to extremes, had only 10ppm of Ca etc and had 50ppmm or more K+, but these are out of the range of parameters as it is, folks should have enough Ca to begin with before squawking about Ca/K+ issues. 

Now if you are using KCL, then that might be the issue, the Cl, but not the K.

I use K2SO4 and always will.

I am not certain where these hair brained notions come from but folks might want to try it out before assuming that K/Ca inhibition exist in aquariums unless you really try to go extremes and quit using terrestrial plants and K/Ca gated channels or IPI which are not nutrient uptake competition at all.

I keep about 20ppm or so these days and have for the last few years. My rec's for folks dosing reflect this. ??No water changes is asking for but some folks can get away with it for awhile but their tanks always look better if they do the water changes and dosing a good frequent routine.

Bark up another tree if your GH is 3 or higher and you have a K+ of around 20ppm-30ppm.
We've done this(SFBAAPS) for 8 years or so with 20 + folks with wide ranging water types. I'm telling ya, this ain't it. 

Regards, 
Tom Barr


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## JamesHoftiezer (Feb 2, 2003)

Thanks Tom. As far as I'm concerned that's the end of the discussion. As a newbie it great to have you around.

As I said before I need to get into a documented fertilization regimen. I'll pay more attention to the K levels and increase the number of regular water changes. I'll still dose the trace daily, but cut back on the K based on tank volume in relation to the water changes.

I'm pearling great right now and haven't added K2SO4 or KNO3 in two days. The rotala.indica looked great for the pictures. I'll do a full test array tomorrow and find out where I am on everything.

*James Hoftiezer

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## wetmanNY (Feb 1, 2003)

http://www.igzev.de/englisch/projektea.php?mid=5

At the German research instute IGZ, a project titled "Growth, assimilate partitioning and yield of tomato depending on K/Ca supply" is currently being run by Hans-Peter KlÃ¤ring, who states the common knowledge in the hydroponics field, "Concentration and ratio of potassium and calcium in nutrient solution affect their own uptake and that of other ions."

The possibility of cations being in competition with chloride, an anion, is most unusual.

And the phrase "hair-brained" is more generally rendered _hare-brained._


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## Roger Miller (Jun 19, 2004)

> quote:
> 
> Now if you are using KCL, then that might be the issue, the Cl, but not the K.


Tom,
Can you produce some evidence for that assertion?

Roger Miller


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## Guest (Apr 30, 2003)

Nope, don't use KCL.
Seems Cl anions "might" effect plants to a greater degree than the SO4. I won't discount that it will not.

But give me some time and I'll get some info up on Cl. But generally I am aware it(Cl) can be quite high without adverse effects in my tanks.
Just like a little salt(NaCl).

What is your Cl levels there Roger? I recall you have high Na.

But I have not personally used KCL over a long period so I will not discount the potential effects.
K2SO4, I know and know well.

Lycopersium hydroponic solution mixes are not even close to aquariums. The concentration levels are also a function of the reservivor size and evapotranspitrational rates of the plant growing system. Scott at Beylik hydroponics in Fillmore CA is one of the best Tomatoes growers using organic hydroponic methods. Nice guy too. 

Regards, 
Tom Barr


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## Roger Miller (Jun 19, 2004)

> quote:
> 
> What is your Cl levels there Roger? I recall you have high Na.


My tap water is in the area of 15-20 ppm. Not high by most standards. Tap water can go up to 250 ppm before regulators raise an eyebrow. I'm not currently adding any chloride 'cept for what may be in fish food and Flourish products.

The water utility changed my water supply last fall. The water quality report hasn't been updated since then. The hardness increased to nearly balance the alkalinity. I haven't had any problems from high Na since then, and I hope it stays that way.

Roger Miller


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## Guest (May 1, 2003)

Well I poked around and did not find too much issue with Cl- anions.
Mainly an irrigation issue. I recall some hydrologist complaining about the water having high Cl- but it was being used for irrigation and the place had high evaporation so Cl accumulated in the top soil. 

So that's not likely an issue. Found some work on Cl- inhibiting NO3- uptake.

No good stuff on K and Ca inhibition that was relavent within ranges here.
K+ transport/uptake and such is perhaps one of the best understood nutrients but I had not found anything yet for aquatics but did find some Mn2+ Ca2+ research work that might indicate some inhibition in the form of competing for the the same transporter.
The same can be said of Cu and Fe actually.

I'll keep looking but I have been through a number of books and my gut says no way after all the nutrient business I've done thus far.

My bet is on something else but I also think there's not need for more than 20ppm K+.
I add around this and a little less with my own routines(11-22ppm by estimation).

I've gone much higher for exteneded periods, so have many others with soft SF tap water running their GH's around 2-3.
So have many Discus folks that like to ride the lower end but have added a fair amount of K.

So even if I find something close to applicable, I'm going to be suspicious(Even of myself).

The Observations rule. "Why" is much more debatable

Regards, 
Tom Barr


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## Madpiano (Feb 4, 2003)

hmm, that had me interested. 

I can see a problem with the Cl-. Ca is a positive Ion, CL is negative. Aren't they attracted to each other ? And what do they produce when they connect ? Maybe they produce something which is not usable to the plants ?

I was allways weak at chemistry, so I don't know, but maybe CaCl is different to Plants than whatever it produces by connecting with SO4 ? Or maybe the plants even use some of the sulfate ? Whereas Cl is essentially bleach, isn't it ?


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## Roger Miller (Jun 19, 2004)

The Ca++ and Cl- don't "connect" in solution. Cl- (chloride) is not bleach and cannot accidentally turn into bleach. It is harmless.

Roger Miller


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