DIY Potassium Solution?

[arkaeus]

After a few searches with few results, I figured I would ask...
I see most Potassium solutions are Potassium Sulfate, and Chloride. Do we have a DIY formula floating around? POTASH SOLUTION GRADE 0-0-50 Sulfate of Potash OMRI LISTED SOP an option?

[disc1]

I would assume the mixture is to maintain chloride to sulfate ratios after dosing. I don't know if there is a formula already out there but I could match one up with the magnesium solution from Randy's two part article when I get a few minutes. If you don't find anything else today I'll try to figure that out and post tonight.

[arkaeus]

Thank you for the help. I'm in no rush, im just trying to decide if going this route would be worth it for a large tank dosing Zeo.
Once again thank you for your time =p

[daido]

There isn't such a big difference in cost 2lbs of potassium supplement cost about 13$

[arkaeus]

250ml 42.99$
500ml 73.99$

How is 2lbs for 13$ not a huge difference? Maybe your saying its not as highly concentrated and I will have to use more?

[Allmost]

i am not sure about this, but I have seen discussions, which point that K+ in the KZ's potassium is not KCL.

I have also seen claims that "extra chloride can make corals brown"

again, not sure, and I do not know what other sources of potassium there are ... Maybe David can suggest some alternative ?

not KNO3 lol

[disc1]

Originally Posted by Allmost

i am not sure about this, but I have seen discussions, which point that K+ in the KZ's potassium is not KCL.

I have also seen claims that "extra chloride can make corals brown"

again, not sure, and I do not know what other sources of potassium there are ... Maybe David can suggest some alternative ?

not KNO3 lol

Given the amount of chloride present in seawater I wouldn't expect the tiny amount coming from a potassium supplement to really make any difference. It would be a very small drop in a very large bucket.

For instance many people use calcium chloride for calcium and even that amount of extra chloride I haven't heard of it making any huge issues.

[daido]

Listen! Potassium is an important element to dose a red sea supplement of potassium costs 13$ and it is a powder so it will last for a long time. Use a good test kit like the one that red sea makes.

[arkaeus]

From what I understand Potassium in most tanks is not something that is depleted quickly. In a zeovit system, dosing the main 4, potassium deficiency creeps up fast.
I have never used K-Balance strong solution yet. I understand every tank is different. I just had a friend accidentally leave his doser with K-balance plugged in and dosed half a bottle. His Potassium levels were still low. This got me thinking, if I start having to use this everyday it will get expensive fast.
I may be wrong, and over thinking this.....

[Allmost]

Originally Posted by disc1

Given the amount of chloride present in seawater I wouldn't expect the tiny amount coming from a potassium supplement to really make any difference. It would be a very small drop in a very large bucket.

For instance many people use calcium chloride for calcium and even that amount of extra chloride I haven't heard of it making any huge issues.

thank you as always David

I have to review my organic chemistry but would dosing KCL, to bring K+ from 390 to 400, increase chloride concentration by 10 PPM as well ?

[Allmost]

Originally Posted by arkaeus

From what I understand Potassium in most tanks is not something that is depleted quickly. In a zeovit system, dosing the main 4, potassium deficiency creeps up fast.
I have never used K-Balance strong solution yet. I understand every tank is different. I just had a friend accidentally leave his doser with K-balance plugged in and dosed half a bottle. His Potassium levels were still low. This got me thinking, if I start having to use this everyday it will get expensive fast.
I may be wrong, and over thinking this.....

yea I dose 10 ml a day of K balance strong in about 200 Gallon of net water.

[arkaeus]

Originally Posted by Allmost

yea I dose 10 ml a day of K balance strong in about 200 Gallon of net water.

This is what I'm afraid of. My setup is around 320 gallons net vol. If I will need to dose that much we are talking 70$ every month and a half. Its not so much the cost, its if I can do this considerably cheaper by a DIY mixture.

[disc1]

Originally Posted by Allmost

thank you as always David

I have to review my organic chemistry but would dosing KCL, to bring K+ from 390 to 400, increase chloride concentration by 10 PPM as well ?

You have to take their atomic weights into consideration, although they are almost the same.

K is 39.1g/mol and Cl is 35.5g/mol

Using those figures I get a 10ppm increase in K with KCl works out to a (10 * 35.5 / 39.1) = 9 ppm increase in chloride.

Chloride is in seawater at 19,400ppm. So the change in chloride from that addition would be 0.046%.

[disc1]

OK, here's what I got. Bear in mind that I don't dose K myself and that the ONLY consideration in this formulation was matching sulfate and chloride ratios.

The mole ratio of chloride to sulfate in seawater is 19.36 : 1.

So the ratio of KCl to K2SO4 that would match that ratio is 8.3: 1 by weight.

8.3g of KCl plus 1g of K2SO4 would have 4.805g of K in it.

We could easily get about thirty times that in 1L of solution. So let's say we did 250g KCl + 30g K2SO4 in 1L. That would have 144g of K per Liter in it or be 144000ppm.

1 mL of this solution would have 144mg of K so it would raise the K in 100 gallons by 0.38ppm. To make a 1ppm adjustment to 100ga would take 2.64mL.

It might work out at double, triple, or even quadruple that strength. I'm being a little conservative with the solubility numbers.

Anybody see any holes in that?

[disc1]

Originally Posted by Allmost

not KNO3 lol

K2HPO4??? Lol. I'm kidding.

I wonder if K2CO3 would be an option. You would have to calculate your potassium dosage and how much alkalinity that was adding and cut two part by that amount. But that's not unreasonably hard math to do. And if you had that math worked out for your tank you could do it together with your two part by replacing some of the sodium carbonate.

[Allmost]

man you are great !

thanks for the math and the K2co3 Idea!

Im gonna see if I can find that locally.

thanks again

[disc1]

Searching for potassium carbonate or pearlash didn't turn up much. Searching for potassium bicarbonate (KHCO3) on the other hand turned up a bunch of results for everything from home brewing to gardening. That would work the same way only it would add half the alkalinity as carbonate for the same dosage and wouldn't have any pH effects. That might actually be a good thing. It could also be turned into carbonate by the exact same baking method we use for sodium bicarb if one was so inclined.

[Allmost]

I found this on wikipedia
"Potassium bicarbonate is an effective fungicide against powdery mildew and apple scab, allowed for use in organic farming."

maybe at large doses it can kill mildew ? will it cause any ISsues in our reef tanks you think ?

"Aids in the prevention of mildew and fungus. Great for roses and crape myrtles. Helps to prevent and control brown patch in lawns. Application Rate: 2 level tbs. to a gal. of water. One gal. of mix will cover 460 sq. ft. Add 1 tsp. soap to aid in adhesion"

9 bucks for a pound of it here.


Safety Data sheet.

Arm and hammer also makes a product called Flow-K-potassium bicarbonate

found some K2CO3 as well, contains :
Purity: 99%min ; Sulphate: 0.04%max ; Chloride: 0.03%max ; Insoluble matter: 0.04%max ; Burnt loss: 0.7%max ; Iron: 0.001%max

[disc1]

Originally Posted by Allmost

will it cause any ISsues in our reef tanks you think ?

No way. Both of those ions are always present in seawater and that molecule will fully dissociate when dissolved. There's absolutely no difference if they came from sodium bicarb and potassium chloride or sodium chloride and potassium bicarb.

[disc1]

Originally Posted by Allmost

thank you as always David

I have to review my organic chemistry but would dosing KCL, to bring K+ from 390 to 400, increase chloride concentration by 10 PPM as well ?

So back to 10ppm. If we did that with KHCO3 it would take...

For One Liter:
10mg K is (10 / 39mg/mmol) 0.256mmol. That means there would be 0.256meq of alkalinity added as well. That's actually quite a bit. That's around 0.7dkH!!! That is significant.

Also we can figure that 0.256mmol of KHCO3 is 0.256mmol * 100mg/mmol which is 25.6mg of the KHCO3 per liter of water. Or 0.0256 * 380 = 9.7g for 100 gallons.

Personally I am not too worried about K in my tank. But if you are going to dose it, and you don't mind the math involved in adjusting your alkalinity dose, then I think KHCO3 is a fine way to do it. If they are using it in homebrew, then there has to be a food grade quality of it.

[disc1]

Originally Posted by Allmost

Arm and hammer also makes a product called Flow-K-potassium bicarbonate

found some K2CO3 as well, contains :
Purity: 99%min ; Sulphate: 0.04%max ; Chloride: 0.03%max ; Insoluble matter: 0.04%max ; Burnt loss: 0.7%max ; Iron: 0.001%max

That breakdown looks totally acceptable.

[Allmost]

thanks for all your help

Im gonna give it a try and report back.

[jerpa]

Somewhere a Zeovit chemist is shedding a tear...

[Steveb]

Originally Posted by Allmost

I found this on wikipedia
"Potassium bicarbonate is an effective fungicide against powdery mildew and apple scab, allowed for use in organic farming."

maybe at large doses it can kill mildew ? will it cause any ISsues in our reef tanks you think ?

"Aids in the prevention of mildew and fungus. Great for roses and crape myrtles. Helps to prevent and control brown patch in lawns. Application Rate: 2 level tbs. to a gal. of water. One gal. of mix will cover 460 sq. ft. Add 1 tsp. soap to aid in adhesion"

9 bucks for a pound of it here.


Safety Data sheet.

Arm and hammer also makes a product called Flow-K-potassium bicarbonate

found some K2CO3 as well, contains :
Purity: 99%min ; Sulphate: 0.04%max ; Chloride: 0.03%max ; Insoluble matter: 0.04%max ; Burnt loss: 0.7%max ; Iron: 0.001%max

Thought I would share found it for 6.99/lb here .

[cthedaytrader]

http://www.reefcentral.com/forums/sh...ight=potassium

Might want to check out this thread as well, Randy had mentioned Potassium Bicarbonate in it as well. Im not sure, but if you have to raise your Potassium a lot, you may also be providing a large boost in Alkalinity, which I would assume may be the limiting factor in using it in some tanks?