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How much K2SO4 to add in EI for Potassium Deficiency?

1618 Views 6 Replies 4 Participants Last post by  Naja002
The plants in one of my tanks, a 75 gallon, which I've kept with great success up to now, seem to be suffering from a Potassium deficiency, which would make sense as the plant density has increased and I haven't been adding an extra source of K. Up to now I've added 3/4 teaspoon Potassium Nitrate and 1/4 Mono Potassium Phosphate every other day, Seachem Flourish 7.5 ml on the other days. How much Potassium Sulfate should I add? I read somewhere on the forum that I should be adding 1/4 teaspoon together with the Potassium Nitrate and Mono Potassium Phosphate.
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I haven't/can't prove/disprove anything, but a target level of 30ppm seems to work well for me. Its slightly higher than what EI calls for according to my dealings with the fertilator.

Thanks, how much is that in teaspoons every other day?
How much K2SO4 is what I meant. My plants don't seem to be getting much K from KNO3.
30 ppm???? That is alot. By the EI charts I have seen, for a tank that size 1/4 tsp of K2SO4 is what is suggested.

By my calculations, 1/4 tsp of K2SO4 with the other dosing parameters you have given, will get you just shy of 10ppm in a 75 gallon (excluding your water conditions).

Can someone verify this though....
Have you tried using Chuck's calculator to assess your dosing? It's pretty great. According to his calculator, 1/4 teaspoon of K2SO4 only doses 2.37 ppm of K in 75 gallons
30 ppm???? That is alot.
That's 30ppm per week target. The EI dosages for the 60-80gal. and the fertilator set at 75gal tank=26.7ppm per week. I find a bit more helpful. That's on multiple setups, over the long-term. Even then, some plants seem to want more....that's been my experience.

According to the fertilator: 3tsp per week will net You ~30.34ppm/wk.

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