I got my tank-raised Bimac. from fishsupply.com last week. Named Pixel, right now his mantle is about 1.25 inches long and his legs are about 2.5 inches each or so. (I never knew how hard it could be to estimate size of something). My guess is that Pixel was hatched the first week of September. Right now I have him in a 75 gallon tank with some companions. He is currently quarantined off in a plastic terrarium completely submerged in the tank. The terrarium is probably about 7 gallons or so. Other creatures in the tank: 2 Sergeant Majors (a type of Damselfish), 2 Sally Golightly crabs, and two Turbo Snails. The fish are a little over an inch long each, and the crabs are probably about 3" across. I originally put Pixel in the terrarium to protect him from the fish and the crabs. The fish are pretty territorial, and the crabs are probably about the same size as the octopus. I am wondering when it would be best to let Pixel out into the main tank.