Hey, I have a butterfly too! :lol: I keep a CBB. :)

The best reef safe choice is supposedly Hemitauricthys polylepis, the pyramid butterfly.

But I'm afraid to say I too believe none belong in a 40g cube, sorry man. Just too big of a fish.

Thanks guys.. I have scrapped that idea.. I'll come up with something else unique I guess...

O I know a guy who keeps copper band butterflies in his reef tanks with no problems.

Yea, I should have mentioned in my first post I was thinking of butterflies other than the very common CBB. :lol:

I believe Carmen has one(CBB) in her tank too.

yup! Awesome little guy never touches anything other than Mysis!:wink:

I've kept various Butterflies in my reef tanks for years.

My Long Nose didn't touch my corals but harassed my clams.

My Saddle Back would munch on my hammers occasionally & sometimes would forage around the clam's shell but would leave everything else alone.

Ditto the Double Saddle Back I had.

My Racoons didn't touch any corals or clams except for the occasional nibble at my hammers.

My Copperband annoyed my clams but left anything else alone.

My Heniochus Dipherutes was totally fine in my reef & even my Heniochus Acumitatus left my corals alone. The Acumitatus are known for chomping on corals though so i guess I got lucky with that particular one.

The only problems I had was trying to get my Racoon to eat at first but other than that they all ate like pigs (esp. the Heniochus).

I'm planning on trying a C. Auriga in my next tank (definitely not reef safe!)

It'll start as a FOWLR Butterfly-centric tank but I'll slowly introduce corals & if they get nipped I'll just remove them and put them in my reef tank.

.

Mrfish55 is right your system might be a little too small for any butterflie. As for it being in a reef I think it all depends on the fish itself Cause I have a Bennetti and a Copperbanded in my reef tank and they don't seem to be hurting anyone, all my feather duster are still there. I also have a 6" Gold flake cruising the tank ass will and I was told he would destroy my polyps, but the only thing he has destroyed so far is my wallet, from all the hakari krill and mysis shrimp he's been eating.
But best of luck though