# Can you have too much Potassium?



## GulfCoastAquarian (Jul 30, 2002)

It is possible to have too much K, because it can block the uptake of Calcium at high concentrations.


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## malkore (Nov 3, 2003)

too much potassium won't cause algae, but does cause calcium uptake problems.
I'd suggest after a water change, you dose about 15ppm of potassium. Then halfway to the next water change, dose another 5-10ppm

Just watch for calcium deficiencies...which is usually seen as new growth with curled up leaves.


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## aquabillpers (Nov 28, 2003)

Insufficient phosphates will also "cause" algae, because plants need it. It would be a good idea to check to see what level you have. Aim for about .5 ppm.

From what I've read, excessive potassium is rarely a problem and when it is, it has to be really excessive!

Good luck!

Bill


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## Hypancistrus (Oct 28, 2004)

You will find varying opinions, I've read that 20-50 ppm for a planted tank is "optimal," and I've read other opinions that nothing more than 2 ppm is "optimal." Since it can't really be accurately measured cheaply, I simply dose Seachem Potassium 3 times per week at the recommended dose. I do a 36% water change weekly.


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## malkore (Nov 3, 2003)

Hmmm, never heard anything over 20ppm for potassium, and I know a lot of poeple that don't go over 10 or 15ppm.

and yes, low phosphates will lead to nitrate induced algae blooms. This is why we refer to algae being caused by a nutrient imbalance, rather than something being too high.


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## aquabillpers (Nov 28, 2003)

What test kits are people using to measure potassium levels?

LaMotte used to offer one, but their web site no longer lists any. Some users of it reported that it was quite cumbersome to use, and they settled for a "enough" (white precipitate) or a "not enough" measurement.

A search of That Fish Place's site brought up almost 100 test kits, but none for potassium.

Bill


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## malkore (Nov 3, 2003)

we don't test for potassium. you just estimate how much you'd need. after a 50% water change, most of your potassium will be gone...so dose 10-15ppm.


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## grungefreek (Oct 9, 2003)

Is there a web page somewhere that says that an excess in one fert results in the insufficient takeup of another???? Ive seen a few taht show deficiency signs, but none that say an excess in say pottassium leads to insufficient calcium uptake.


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