Ok, I might need some help here. I'm thinking of upgrading my 55 gal. I can't go too big, 'cause the wife would kill me. Anyway, I thought I'd keep the 55 as a sump/fuge, but it all depends on if I can get a deal on a whole setup. Here's my problem, though...

I have a deep sand bed (approx. 6 inches) and I don't know how I would transfer everything to the new tank. Wouldn't the denitrifying bacteria all die off in the move to the new tank? That it, I don't know how I would move it without oxygenating the whole sand bed. Anyone have any thoughts here?

The other thing is cycling. What do I do with my lifestock while the new tank is cycling? Whatever bacteria I have in the 55 certainly will not be enough to support, say a 90 gallon. And I know that the amount of bacteria is a function of the livestock. The more livestock you have, the more bacteria you will need. But, as the first increases, so will the latter. What I'm thinking is the liverock I'll need to add. (As I'm typing, I think I'm answering my some of own questions.) I guess I just add cured live rock, huh?

What about lights, though? Metal halides vs. T-5's? I probably can't go any bigger than 125 g, so what do you all think here? What am I looking at in cost? (Roughly.) Any thoughts would be greatly appreciated.