I've got a problem with my 20 gallon excel tank which I converted from a Walstad type tank about 2 months ago. I'm getting very little growth for the most part, I have an H. difformis which looks wilted and growth is pretty much stunted all around. I see no yellowing of leaves or signs of decay. I do 50% water changes/week. Gh is 3.

I dose the following for 20 gallons:

excel - per instructions
tropica - 2 ml x2
k2so4 3/8 tsp x1

I had to stop dosing N and P because my levels have been running very high. I'm currently adding K2SO4 since I'm not dosing KNO3. I don't believe I'm overfeeding or am overstocked. I suspect there may be some other nutrient problem intefering with N uptake, but I don't know what it might be. Calcium, Mg ? I thought this sort of stunted growth woul indicate a Macro nutrient problem. I'm stumped.


Henry