Downsizing help me decide

Thanks for your thoughts everyone. I do appreciate the input. That size would have to be a custom tank (48 x 18 x 18) and I don't really want to go there.

I also looked at the dimensions of the 55 and it's too narrow. The 75 is only 3 inches shorter, if I added a sand bed it would be pretty much the same thing. When your fish start nibbling at your armpits, you know your not fresh right?

I guess I'll just hang onto the 90 and start a journal.