Thanks. I personally do maintenance on my aquariums and I find it more difficult to deal with anything over 20" high. so that right there affects the water volume. I went from a 20" high 27 gal
cube to 16" high 40 gallon breeder and boy what a difference.
My main goal is to have enough room for rock work (18" min depth) and enough room for a bristle tooth tang. Only other tang I like is Purple Tang but I hear they can be mean and require lots of swimming space.
Also, I want to have a nice reef with not much fish. With type of corals I buy I run out of space quickly. Look at photo below. I purchased a couple decent sized corals and pretty much maxed out right then and there. So disappointing. I wish I had done 75 gallons.