ohhhhh Im sorry i misread the post. I thought it said 24 gallon. I have kept an aculeatus in a 39 gallon CAD system and it did great. It was extremely interactive too. I kept a giganted anemone, clown pair, banggaii cardinals, Mcoskers flasher wrasse, and multiple sps corals. The octopus took frozen silversides from tongs instantly when i rubbed it onto its tentacles. It also was indifferent to every fish except a lawnmower blenny which went into the den and never came out.
Sorry for the misinformation
Good luck