I think more people would say "no" you can't have two tangs in a 75 than "yes". Tangs tend to be very aggresive towards each other. It is a very risky thing to do. However, it does work sometimes. Body shape and size has alot to do with it. I've been very fortunate with my yellow tang and my Naso, them both getting along fine in a 75 gal. I also have about 100#s of live rock in the tank.