I have a 10g under my 65 (the 15T wouldn't fit). It is a fine place for heaters, macro, return pump, etc. "Works" for me. It really depends on what you're looking to get out of it! Otherwise you could have something custom built out of Acrylic. One of the guys in our reef club custom builds sumps and he's got a design for a 2 part sump that gets connected once in the stand.