I have been working on the tank part time for a few weeks. I am getting close to putting the pieces together and filling it up with water. I made the L shape for 2 reasons. 1. You cant see in the pics but there is concrete on the bottom 1/3 of 3 walls. 2 walls are againts foundation wall. I only need to reinforce the front wall. I will reinforce the walls that have concrete holding the bottoms. The concrete was part of the existing basement. Ambient Temperature in Basement 60* - 70* Volume - Approx. 760 Gallons Tank Material - 2x4 studs, 3/4" Vantek plywood, 16 penny galv. spiral nails, 2.5" & 3" deck screws. Insulation - R 11 Fiberglass, 1" Styrofoam, 2" Foil faced , bubble wrap. Liner - Polypropylene 45 Mil reinforced. Hex - 800' 1/2" non barrier pex (should probably use barrier pex) ( 4 coils - 200" each), 2 - Zurn Pex manifolds, 80' 1/2 copper pipe for support, 6" uv rated Panduit tie wraps ( used UV rated because the temp. limitation was 210* instead of 175* for white tie wraps.