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Re: K2PO4 vs KH2PO4
>I bought the wrong stuff. I know I should have ordered K2PO4 instead of
>KH2PO4 for dosing potassium. I have KNO3 for dosing nitrate. I know I can
>use KH2PO4 for phosphate dosing, but what should I do about K-potassium
>dosing? Should I just assume the plants are getting enough from the
>KH2PO4-mono potassium phosphate and KNO3-potassium nitrate?
Did you mean K2SO4 (potassium sulfate) for potassium? Potassium phosphate
isn't a good source of K+.
Anyway, you'll not get appreciable K+ from KH2PO4, but you can get a fair
amount from KNO3. Use Chuck Gadd's dosage calculator to determine how much
-- http://www.csd.net/~cgadd/aqua/art_plant_dosage_calc.htm. If you dose
dry KNO3 directly into the tank, just put 1 in the "Amount of water to mix
Still, it's doubtful you'll get enough K+ from KNO3 alone. In addition to
the potassium that comes from KNO3 doses, I add around 10ppm K+ via K2SO4
after the weekly water change.