I was at the pet store last week and there was a couple looking for fish for their tank. They had a general want to stock their tank properly and asked a lot of questions.
Most of the guys answers were "I dont know" but there were a few doozies.
They had a 20 gallon tank with some different tetras. He suggested they get a RTS for the tank. Told them that it gets about a foot long but when it starts to get too big or they notice it stops growing they are free to bring it back and trade it in for a smaller one.
He told them that they couldn't have platies because they don't share the same water chemistry as the tetras.
He also tried to sell them a common pleco.
I actually striked up a convo with them about honey gouramis and they ended up walking out with 1 of them and seemed pretty happy with the idea of something that would stay in their tank. Then the worker thanked me
1 fish, 2 fish, red fish, blue fish