FYI, Most catfish get HUGE... some like more than 2ft! Pelco's can reach just below 2ft also... Pelcos & red-fin (aka rainbow) sharks also get aggressive/& territorial w/age. The albino ones get about 4in long, but don't like the high garbage load of goldies, and prefer the water to be warmer, up toward 80 F.
Pelcos (and other algae eaters) & goldies should NEVER be together, because as they get older, they tire of the algae, and begin to suck on the slime coats of slower moving fish. Double tailed goldies are an easy catch for them.
Best to do research so you know what fish you are getting, what their needs are, and whom they will get along with best. and when in doubt, ask! Also... I think (but am not sure) that black moors have impared eyesight to begin with, FYI.