I have a 50 or 55 gallon tank with a coralife and glo light system. I have 4 T5 bulbs at 24 watts each. My PH is 7.6, I have a flourite/sand substrate and nutrafin natural carbon dioxide system which I put in almost 3 weeks ago with the flourite. I use Nutrafin Plant Gro iron enriched fertilizer. I have a few types of hygrophilia, 2 types of anubias, a sword plant, 2 bella palms, and what is left of a purple waffle plant. I regularly check the iron level and its good but I haven't checked my nitrates. Are my nitrate levels causing the problem, is my PH too high or do I not have enough light?? The carbon dioxide system is only for 20 gallons but with all my fish I figured it would be enough but maybe it isn't?