Just wondering, are you using an exhaust blower? I keep my moms in a catching trough that came from a constant flow system(sucks). It's 12" wide, 6feet long, but I had to build up the sides to eight inches. It has a nifty little resivoir and legs to keep it sitting properly. I also had to install a barricade at the downward end to hold my rock. I used one inch of regular gravel and the rest, crushed lava rock. Lava rock is about 50 cents a pound Canadian. I only use four foot fouresant cool white tubes24/0 on my moms, ocasionally complimented(at times) by a 400w/mercury vapor bulb18/6, much like a metal halide but frosted. Change the res every five days and make sure you keep it airated. I dump a few gallons through it at a time. You can water as many as three times daily or once every two or three days, depends on desired growth. I keep seven moms in this trough.