Those would probably be fine. A 2 or 3 inch x 3 or 4 inches would work I think...It'd be nice if there were a smallish hole in the back to allow some water movement
I've already decided on the way home today that if it is in fact another male, then I'm returning the remaining two males before the transfer and just having the two from QT as the lone pair, assuming they don't kill each other first. Be it that or it's two females to hopefully make two pairs, I'm not jumping through anymore hoops. This has been more than enough of a wild goose chase just for one species of fish.I don't want to be a buzz kill, but blue spangles could mean a "lesser" male...Like I've said before, females can be little terrors with an unready male...but also with other females...I can't tell. Fingers crossed