Today I stopped by BigAls and purchased a 24'' Coralife F/W T-5 Aqualight Double Strip Light. Looks much better than my old single strip 15 watt light. I am hoping the 3 java ferns in my tank right now will grow even more. I am planning on added many more plants soon and was just wondering if this lighting over my 20 gallon tank is considered low light, because I am not too sure about the difference of T-8, T-10, and T-5, etc.