Well, I guess that would be good on both. Was wondering if 400w would be better on the 150g. See the 150g is 29 deep whereas the 180g is 24. And I really want something simple that I dont have to rewire my house or anything. I dont know much about metal halides at all. But I really liked the marineland marine pro with the timers for each hqi, t5, leds. and oh yeah the built in ballast, so just plug in and your good. Only its 150watt
But with all the other companies out there coming out with new stuff.......I dunno. This will be my final tank build and the only one I will keep...so I wanna do this right from the get go.