I am going to be building a shed for my fish tanks. At first, i was considering getting a shipping container, but I decided that a shed was a better choice. I am going to build the shed after I finish the chicken coop and after I finish the pond and install a UV. In the shed, i want to build a plywood tank that is at least 300 gallons. I am kind of confused on how i seal the inside. I want to use pentair epoxy and fiberglass, but what kind of fiberglass do I use and do I fiberglass the entire tank, or just the seams?