[Wet Thumb Forum]-What happens to the Cl ions in KCl?

[GulfCoastAquarian]

Although I am familiar with chemistry principles, I am not experienced with the biology of how plants react with them.

My question is, after plants utilize the potassium in Potassium Chloride, what happens to the Chloride ions? Is there a chance they bind with Calcium in the water? Ever since I started dosing KCl, my Sunset Hygro (and a few other plants) seem to be showing what might be a Ca deficiency (shriveled, weak new leaves).

I might be way off in my assumptions here, so I thought I'd just ask the question and see what really happens.

Thanks!

-Sam P, BSME
My Website

[GulfCoastAquarian]

Although I am familiar with chemistry principles, I am not experienced with the biology of how plants react with them.

My question is, after plants utilize the potassium in Potassium Chloride, what happens to the Chloride ions? Is there a chance they bind with Calcium in the water? Ever since I started dosing KCl, my Sunset Hygro (and a few other plants) seem to be showing what might be a Ca deficiency (shriveled, weak new leaves).

I might be way off in my assumptions here, so I thought I'd just ask the question and see what really happens.

Thanks!

-Sam P, BSME
My Website

[Roger Miller]

Chloride remains in the water. It doesn't bind with anything unless the concentrations become very high -- like sea water. Even then, chloride forms only weak associations.

What is your hardness? Can you get an analysis of your water supply from the utility? How much KCl are you dosing? Are you adding bicarb?

So many questions...

Roger Miller

[GulfCoastAquarian]

Thanks for the answer to my first question!

My carbonate hardness is around 6-7 dKH (RedSea test), I don't know my general hardness. I got a water analysis of my tap water recently in the mail but can't find it now. What specifically are you looking for?
I am dosing about 1 to 1 1/2 tsp of KCl a week. Not adding any bicarb.

Thanks again!

-Sam P, BSME
My Website

[Roger Miller]

I was looking for general (or total) hardness, sodium concentration, boron concentration and anything else that might give a clue to the distorted growth. Can we eliminate the possibility that you are using a water softener?

Roger Miller

[anonapersona]

Just wanted to note that I'm following the discussion closely, as GulfCoast and I have similar water and since I've gone back to adding KCl I'm seeing white deposits on the top of the driftwood and filter return again. It had gone away while I had stopped KCl. I'm aso seeing pale growth and ragged leaves on some vals and on Apong. Ulvaceus.

Is there any chance that the KCl is acting like a water softener would, taking out Calcium and dropping it as a precipitate?

[Roger Miller]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Is there any chance that the KCl is acting like a water softener would, taking out Calcium and dropping it as a precipitate?<HR></BLOCKQUOTE>

Nope. Could there be a lot of impurities in your KCl?

Roger Miller

[kor4ever]

Correct me if I'm wrong, but don't plants uptake chloride ions for osmotic balance purposes?

I've taken too much organic chemistry and forgotten all my general chem. I agree with Roger that the Ca could not drop out of solution, however, if you dose potassium sulfate, its possible that the addition of KCl will cause the precipitation of calcium sulfate.

I mean, if you have the following equation
1)
CaSO4(s)<->Ca(aq)+SO4(aq)

2)
K2SO4<-> 2K(aq)+SO4(aq)

So according to LeChatelier's Principle, if you add stress to one side of the equilibrium, it will push the equilibrium to the opposite side. However, since all elements in the first column are perfectly soluble, the only way to remove the stress on the right side of the second equation when you add KCl(addition of potassium ions)is to remove the amount of SO4 ions. Thus the equilibrium on the first equation should move to the left and CaSO4 has limited solubility.

However, all conjecture, feel free to correct me if I am wrong.

Felix

20G heavily planted tank with natural gravel and a layer of black sand on top.
DIY C02, Emperor 280 filter(also my CO2 reactor), 4 18' fluorescent tubes(2 Philips P&A, Philips Natural Color, and 1 GE Aquarays).

[This message was edited by kor4ever on Mon March 31 2003 at 09:07 AM.]

[GulfCoastAquarian]

Not using water softener. There are a great deal of impurities in my KCl as far as plants are concerned since this is a table salt subsitute (NoSalt). Sever other board members have used this same brand without difficulties, though. That is not to say some of these extra ingredients aren't possible reacting with my particular water chemistry.
Here are the listed ingredients for my KCl source:

<UL TYPE=SQUARE><LI>Potassium chloride
<LI>Potassium bitartrate
<LI>Adipic Acid
<LI>Fumaric Acid
<LI>Silicon Dioxide
<LI>Mineral Oil[/list]
I did find some tap water analysis from a report a few years back and it listed Copper as 0.130-0.150 ppm. Lead is 3-4 ppb. Not sure if that helps, though. Sorry.

-Sam P, BSME
My Website

[kor4ever]

Not sure if you said Sam, do you dose potassium sulfate?

Copper and Lead wouldn't lead to precipitation of calcium, defintely not at that concentration.

Felix

20G heavily planted tank with natural gravel and a layer of black sand on top.
DIY C02, Emperor 280 filter(also my CO2 reactor), 4 18' fluorescent tubes(2 Philips P&A, Philips Natural Color, and 1 GE Aquarays).