I haven't done a proper dig to see if someone's already made this post, but what are some common (or less common) misconceptions about fishkeeping that you've been made aware of? This is piggy-backing off of my thread about replacing gravel with sand, where
@AbbeysDad brought up a few misconceptions about substrates (particularly sand), and I wanted to make this thread to act as a guide through the misconceptions we've all heard throughout our time keeping fish.
For once, I don't think I have any of my own to share, but I'd love to hear what everyone else has been told.
Please provide the truths to these misconceptions if you can!