mh on a 12g jbj nanocube
 

I plan on setting up my nanocube again, as sort of an "inbetween tanks" tank. My plan is to grow out a few select sps to a decent size so whenever I get the chance to setup my new one I'll have some established colonies to put in it. I was planning on getting a 250w pendant, which will work for my next tank... however I'm a bit concerened it'd be way overkill for the nanocube? how high above the tank do you think i'd need it? 12-24" ? Thanks!

250 sounds like alot of power over a 12, i have a 175 on a 25 and its bright and heats the water up a bit. 250 sounds like it would boil the water.

I have a 175 over a 16 - 6" above the surface. It gets a little warm, but its fiiiine :)

I moded my 12g NC a few years ago to put a 70w mh in the canopy, I added a couple extra fans to help with cooling, however my biggest problem was evapouration.

interesting... I think i'll end up getting the 250, just because I dont want to by MH then have to resell it... just have to experiment with the hight i suppose. I have ATO so evap shouldn't be an issue.