Ok, so I "inherited" what I originally thought was a 90 gallon tank and stand from my boyfriend's brother's renters (they got evicted and left the tank). Turns out that it's more than likely a 120 gallon! We haven't officially measured it yet, but I know for sure it's four-feet long and my boyfriend and I (who are both pretty good at eyeballing measurements) are pretty sure it's 24" wide and 25" deep...which would make it a 120 gallon. This makes me extremely happy, because it's a big tank, but it'll still fit in the space we have for it. Anyway, I'm going to do this tank right, no halfway like I've done in the past. One of the things I've been wanting to try is a 3D DIY background. I have seen how to do it, but I'm having a problem finding the stryofoam. Any ideas on where to get styrofoam for a project like this?