You rally need to forget about wpg because it is irrelevant. Please refer to the chart shown in the thread Dymax Tropical 36 watt | Page 4 | UK Aquatic Plant Society and try to stay in the blue, or at most, between the blue and pink.By what I've read, this is overkill, correct? Would 2 x t5, 54w be better at around 1.8 wpg?
Cheers,