Prepare to explain to people how a pleco is pretty much the worst thing they can add to their aquarium.
Prepare to explain to people that completely draining then dish washing everything in the tank is a bad idea.
Prepare to explain to people that "over filtering" does not compensate for water changes.
I miss my good regulars but for the most part I don't miss working at a lfs.
I already talked customers out of getting the traditional common plecos (usually recommend alternates like albino bushy nose or even otocinclus) as they either ignore algae or only eat it when young than become more open to other foods as well as a huge bioload problem. Have already told people that it isn't necessary to do 100% water changes as it gives stress to the fish as well as a pain lol, have told them to stick with 25-30% water changes biweekly. I always tell customers when choosing a filter always get one that is bigger than the tank is. However, I still tell people to stick with the usual water change routine despite the size of the filter.