Stilgar was in a 20G and I was getting a 40B set-up when had to give him away due to health reasons. At almost 5 in. the 20G looked small and Stilgar could cross halfway in one leap. IMO if you want to do a nice 1/3 dry 2/3 water set-up for a 7 in. male GABF you need a 40B and a 75G is so much better.