Hello, fellow fish nerd. I've had this 20 long for a while and I decided to start fresh and move all my fish to another tank. I love the way otos hang onto the rocks with each other so I decided to buy 7 more to join the original 4 I had. right now I have 11 otos in this soon to be heavily overgrown 20 long. can I squeeze in 4 more? how many can I have in this tank if I am doing 25% water changes every week?