I have a 20 gal. long, a 10 gal and the quarantine tank is a 5 gal. Nothing huge at the moment. My fiance is going to build some big tanks as soon as we get caught up with the bills. I think they will probably end being somewhere close to 40 gal longs. I want two so we can separate the boys and girls. We'll keep the other tanks for the albinos, quarantine, breeding, birthing, and babies. That's the plan. I hope to have them set up by Sept.