Thanks for all the info, I'm going to start ordering everything I need. And you're right $120 to ship 7.5 gallon ughh. I'll be sure to post a new thread when it's done.
I was wondering if this sump was still going strong? I'm having a custom tank made and I really want to build a sump using this method. The only problem is I've never worked with epoxy. It looks like you epoxied all of the wall layers before starting on the bottom of the tank. Did you have to sand the bottom of the walls before adding the bottom layer of epoxy? Does it hurt to make one thick layer instead of three thinner coats? And finally, can I add bulkheads after the sump is epoxied; would drilling be a problem after epoxying the box?