Hey guys, just to make this clear, this is NOT me who is doing it, but my nephew. My nephew is into the hobby as well and thinks he knows a lot and he wants to get around 10 exodon in with his crenicichla saxatilis in a 20 gallon tank. I told him just to keep the crenicichla and not put anything else in it, but he decided to get 4 exodon and now wants 6 more. I told him these won't work out, but he wants to add more so I figured I'd ask on here if that'd be ok just so I can show him that other experienced hobbyists agree it won't work. He thinks because he has a sponge filter and aquaclear 110 that the filtration is ok and the guy at the lfs told him that the exodon and crenicichla will not mess with eachother. So far, the exodon and crenicichla have gotten along fine (or atleast from what I have seen and heard from him).