New Tank & Cycling Questions

[JmeJReefer]

The chromis aren't aggressive. Very easy fish, cheap but cool to look at too. A good start to ur tank.
I've no experience with larger tanks so I can't help ya there...good luck

[Magickiwi]

You could try dosing with a carbon source to keep your bacteria populations up. Vodka specifically was what I was thinking of; but there is a lot to learn about that so do research.