Alright folks... Post your mistakes that you made when you were a newbie... don't be shy... These are the ones you made long long ago perhaps when you got your first fish! No judgment. Entertainment and Wisdom are the goals of this thread. I'll start: - Bought two plecos and tossed them in the pond with the goldfish. They died a month later a cold death in September. (I asked a petsmart guy whats a good fish to clean algae in a pond and that was the suggestion). RIP Plecos.