Tom; I'm setting up a 150gal tank(72"x18"x29"H) and I'm finding out right quick the watts per gal rule seems to fly out the window(no room at the inn). Since I'm using ODNO flourscents It's hard to get 300 watts or better for the plants. It's also a pretty deep tank. Will the 2 w/gal rule evan come close to what I need? I'm trying to do a Lake Tang biotope tank so the plants are V. spiralis, Najas, Lotus, Hydrilla, Ceratophyllum, Myriophylum and lots of surface(on rocks) alge. (talk about a balancing act). The fish load is rather small for the tank but enough to keep the plants happy(and me). I'm trying to keep this tank low maintinance. Where do you thing I could keep the light level at and still get at least modest growth from the plants. I'd like to keep the internode distance close also...Thanks, Jim...PS, Any info on what plants are in the lake would be gratfully acepted from all of you. Especially on mosses and broad leaved plants(Anubias???)