Finally, after 8 years of dreaming about it I own a home and am able to build myself a plywood tank! The material used in 1" birch plywood. Internal dimensions are 80"x46"x30" (what I plan filling it anyhow). After making the shell, I used glass from an old 150 gallon tank for my windows. Used pond shield for the waterproofing, still need to do the top bracing/lid. I then used the same 1" plywood to trim around the top 5" and another 4" bracing on the bottom. End of the month going to build the stand out of 2"x6"s in 2 sections so I can build it outside. Each half will be 26"x85" to give me an inch around the top for wiggle room to place the tank. Haven't fully decided on the height, was thinking in the ball park of 32" or 36". Plumbing will be 2 2" holes out of the back with a weir to skim and allow me to adjust the water level more easily. Each 2" overflow will travel into it's own 75 gallon sump where it will be returned via 1" line back into the tank on each side at the back. Thanks for checking it out!