Tom, I'm looking setting up a 20 gallon tank, using EI and Excel. Looking at light fixtures. Looking at a 40w PC, or 2x 24w T5s (Haven't seen a 24" fixture for 1 T5 bulb). Too much light for Excel tank? Does it matter if it's 2 bulbs? I read somewhere that if it's 2 24w bulbs, it's not as intense as 1 48w bulb. I'm going to try HC and dwarf hairgrass, and I want to have enough light, but obviously not too much. I know you have said under 2wpg for non CO2 tanks, but I have also read on here that the rules are different with smaller tanks. Please let me know what you think about the above, and feel free to recommend something completely different! Thanks very much, Phil EDIT: I found a T5 fixture for 1x 24w bulb (Hagen Glo) , but it's ~$65, and doesn't come with a bulb. The Current Nova Extreme houses 2 bulbs (and includes them), and I can find it for ~$55. Do you know if there is something wrong with the Nova to make it that much cheaper? Trying to cut costs where possible. Let me know what you think. Thanks!