Welcome. We can give much better rules if you tell us about your tank!
20 gal planted-1 Dwarf Puffer, 1 South American Puffer, 2 Red Eye Tetras, 2 Serpae Tetras, 2 Siamese Algae Eaters, and some random ghost shrimp meant as food. Have 2 ten gallons empty so help me decide (maybe Betta and ADF and a shell dwelling Cichlid tank. Open to suggestions) Visit my T-shirt store https://www.moronsarefunny.spreadshirt.com