1st chamber is 3 filter socks, then fuge, then return/skimmer area. I has black walls but the watchmen could probably jump into the return section. What could I use to stop him? Some sort of screen? Also, will reverse lighting actually help, or is it just for keeping the stuff in it? I would sacrifice the lighting. Also, would I be able to keep CLEANER SHRIMP? I tried 2 before, and they actually lasted for a couple of days. My salinity was at 1.021 which could have killed them and then their corpses eaten. Should I try them again? My grouper got up real close to them and didnt do anything. Should I?