honestly i cant tell the difference, nor can remeber, between petco/smart. It is very rare to have a fish employee with actual good knowledge; Ive seen some guy trying to sell a FW shark to a 7 year old girl, whose tank probably isnt that big. The main difference between LFSs and big-box pet stores is the fact that in the latter, their fish tanks and selection suck. true, they keep their tanks clean, but the fish themselves are in poor health, are suffering malnutrition, or plain dead. All the tanks are hooked up to each other so if one tank gets infected, all of them do. Their fish selection is abysmal too. Just your plain selection, common fish such as baby Oscars for $5 with no information about them whatsoever, mollies, GloFish (for more then a LFS), some tetras, and "assorted cichlids".