i have 4 metal halide 400 watts and 3 250 with lumenarch i only run it 6 hours each on 1 hour interval.as par as the tomini's its always a gamble, just make sure that you can catch it if they don't get along.i had a schoal of yellow and purple tang before they get along i though but they died after couple of weeks but maybe theyget bullied by my old yt and pt or i got a bad bunch because my old yt and pt still alive.