I have a split unit AC, it has dry cycle options but it doesnt seem to bring the the humidity down. My 50 gallon tanks are in the room, but have tops on them. Holes are cut out just big enough to fit PVC for the pumps. My tables are on slanted tables and I make sure to dump all the water from the waste. I'm still dumb founded why the its so high in the room. I have 4 16 inch circulating fans in the room.