A nano reef with live rock, corals and 2 clownfish, some turbo snails, and a firefish...if you are doing a 29 gallon, live rock, corals, coral beuty dwarf angelfish, 2 clowenfish, firefish, six line wrass(six lines are sometimes aggressive so it is a risk...) I have this in my 29 gallon, six line sometimes bullies firefish but it is not too bad...