planing for fish in 40 gal tank

[EmilyB]

I have two (small) triggers in a 120g right now with some other fish. They do a fair enough job of polluting that one, even with a Euro-reef skimmer.....

Quinn might be thinking of my valentini puffer, which would be a good choice for a 40g. This fish is not compatible with triggers or other hugely aggressive fish. There are small wrasses that may be a good choice, I don't know. My valentini currently resides with a yellow tail damsel, and a coral banded shrimp of all things...

The death of a box fish in a small tank can unfortunately mean the demise of all your occupants in short order.

Re the CBB: I believe the copperband to be "largely" reef safe. I have one in my 155g for a while now, the only thing it has bothered was the open brain. I eradicated all the xenia from that tank, so I can't comment on that, however my Black Back butterfly thinks it's spaghetti. The CBB are a lively fish filled with personality.