I wouldnt keep a dogface in anything smaller than 100-125 gallons. These guys can easily reach a foot in length. This site has a striped dogface (or Manila) puffer that, IMO, is a very under-rated member of the family. It doesn't get as big, is quite inexpensive and has all the puffer personality. They are really pretty fish; but I can never remember seeing a good pic of one.(The pic on this site is terrible, IMO; but I got the fish here and he's great.)I think this fish would be fine in a 75. It has the bad rap of, like most puffers, being a messy eater. But, I always have other fish that will get any leftovers anyhow; and the only difference between food that a fish misses and the food that passes thru him is the small % absorbed. A way over rated concern, IMO, but I know there is a strong argument on the opposite side.