Bought a couple tanks in March, a 55g and 30g(36w x 12d x 16h). Got the 50g going immediately, and have Vals, crypt, and sword plants under 4x 13w 5000k CFL mounted horizontally, 10 hours light. Plants growing well. The 30g I had 3/4 water and various plants ( mostly vals) floating under single T8 Aqua glow light at 10 hrs/day. April 7 decided to start 33g with PFS and planted tank (and seeded filter)...plants growing. Apr 14 switched 33g to 2x CFL 13w 5000k mounted horizontally. Plants doing ok. Added couple sword plants week or so ago. Now plants seem to be dying off. WC was approx 50%/week but bio load very low with 2 Kribs and approx 8 guppies. Have now reduced WC to 25% per week and upped light to 12 hrs. Is it possible too much light and should I reduce light to 8 hrs? No ferts are added. Oh yes, added an air stone last week too just for surface agitation. Filtration Fluval205. Any ideas or suggestions? Thanks everyone.