Agree with Trottie 110%!!! If you outgrew a 75g, then you have to ask yourself if you can afford something in the 120-200+g size. You are either going to go with more depth on say a 120g, or more length and depth with a standard 180g. The stock sizes of 7-8ft tanks are between 200-240 gallons unless you custom order. Remember also, that with larger tanks comes more RODI, more saltmix, more electricity, more supplements, more liverock and more evaporation....lots of things to consider when jumping from a standard tank into the big boys.