Got a spare 38g and planning to use as a growout tank with pressurized co2 and ferts. Would a 96w pc fixture be sufficient? Not a display tank and not looking to get color out of plants. Just to grow them.
The tank is 18 inches high, so if you have 3 inches of substrate, and the light sits on the top of the tank, it will be 15 inches from the substrate. So you probably want a 36 inch long light, and one that will give you 40 - 80 micromols of PAR at 15 inches distance. Look at the charts in Lighting an Aquarium with PAR instead of Watts to see what would work. Also, for a good LED light, look at the charts in Finnex RAY II & FugeRAY PAR Data