Hole in the Head often occurs in aquariums with under gravel filters, and sometimes in aquariums with canister filters, but rarely in aquariums with a BIO-Wheel filters.One large Oscar 8 inches in length needs at least 80 gallons of water hope this help HITH sucks

Most of the petstores around my area seem to neglect their fish half the time. One petshop once had all their angelfish infected with fungus, so much that one of poor angel's tail was completely eaten away by infection. No sign was posted either that these fish were sick or not for sale. It was sad...And I fear that's how they'll treat my fish if I take them there.
Is it Ok for an 80 gallon to be run by a HOB power filter? Or does that size of a tank need a canister or something?