I made a little one for my tank. and then I built a little top off tank and little stand for the pump (not shown here) Now, I'm just a hobby type guy - not a professional. So you looking at 65 gal SIZE (dimensions) or for the sump to have 65 gallon as working volume? If so it needs to be bigger. And which way you go determines the thickness of the material.
Looks great...looking to do this 48 X 18 X 18 with 5 dividers. Can't upload any pictures because site has me blocked from uploading any more pics!!!! I can get glass cages to build this, just didn't know if anyone locally could do it. My 150 will be in before the end of the month Really need to get this going.