Join Date: Nov 2006
Location: Bialystok (White Hill :) ), Poland
The more potassium the paler the plants - why is this ???
I have very infuriating problem: the more potassium i add the paler colors my plants get. I add 2 ppm K daily from KHCO3. I had the same problem in my old tank. I know EI followers will tell me there is not enough PO4, NO3 or CO2 but it is NOT the case. I added heavy doses of NO3 and PO4 but without effect.
The symptoms on plants resemble iron deficiency but it looks somewhat different - all the new leaves are uniformly yellow while classic iron deficiency always caused leaves to be partly yellow (on most plants). When i decreased K doses the plants got better colors but they quickly showed K deficiency symptoms. I don't have issues with stunted tips or deformed leaves (which are commonly considered to be caused by excess K).
Of course i tried to add more iron and manganese (about 0.5 ppm Fe - water in the tank was slightly yellow due to dissolved iron chelate (DTPA) ). But it didn't work - chlorosis still existed. Did you have similar problem ?