This build was inspired by all of your builds. And my buddy who sold the idea to me, and helped with the build. Most of my research was done on this forum. I used birch plywood. that was coated with 5 coats of west systems epoxy resin. I opted to make each panel water proof independently, relying on silicone to handle the rest. I learned several things with this 135 gallon build that I will apply to the next one. first of all, apply resin before clamping together to pre drill and countersink. secondly apply my finish before I assemble. Thirdly, polyurethane was clearly produced just to make me re sand a million times. I will never use it again. In the end the biggest issue for me was how to build my ugf. The pvc frame work was easy. I drilled holes 1/4 inch holes every inch or so in the pipe and put in 3 open tees. For gravel plates, i struggled. I considered acrylic but that was pretty spendy for something thick enough to handle my basalt rocks that were going in. And my wife was losing patience with my spending. Eventually I settled on three 24" x 18" x 1/2" poly-carbonate cutting boards. Using a 1 3/8" hole saw I drilled for the up lift tubes. And randomly drilled 3/16th holes everywhere. It was a fun build I cant wait to build a 800 gallon tank one day. Thank you all for your help and information. Please ignore the cloudy water. The substrate is river rock from home depot and I did not do a great job rinsing it lol. 
