Hello all :)

I have a question, I know its a deficiency in my crypts. Their leaf tips are curling down...now I have read that this is a Nitrogen deficiency. But my tank is low light, I use Flourish root tabs every 4-6 weeks, and dose Flourish Comprehensive and potassium every 5 days. My lighting is 96watts over a 55G tank at 5500K, and my substrate is 100% flourite. I *shouldnt* have a deficiency by traditional standards. I didnt notice this leaf curling until I started using Seachem Prime, could it be removing some essential nutrients from the water because we all know it removes everything under the sun. Should I switch to a more general dechlorinator? Consequently my 15G planted is flourishing. Any ideas?

I plan to do a remodel on this tank in the next few weeks, whenever this darn manzanita sinks. I will be adding an additional bag of flourite and re-aranging everything and would like to have a good concept of whats going on before I dive into this next phase. Thanks :)