It is a gbta. I am running the Fluval Sea lighting with about 8hrs white, 8hrs blue, and 8 off. I have just 1 powerhead for now but I'm going to add another in a couple weeks on the otherside to give the wave effect. In a 36gal bowfront tank, I just added 2 clowns today but I don't think it's open enough for them to even try to host.