I'll second him on the Krylon Fusion. Works great! Use several light coats, letting them dry about 5-10 minutes between each. And I would let the paint sit for at least a couple days before sticking it in your tank... I wait till it doesn't reek of paint anymore before placing a painted object in the water just for my own comfort of thinking it's not putting off toxins anymore
I've only used generic spraypaint. Black, and O.D. Green. Never had any problems, and I've never bothered to clear coat either.
As a matter of fact, yes, I always post, or reply, in novels. I'm adding it to my signature because it seems like I say it in every post!
Fraternity of dirt #32 I'm dirty UGLY TANK DIY Asian themed aquarium stand