Hello, I am planning change my 15 gallon tank for a 50 gallon tank to suit a new pumped shower. My plan is to place three 3x2's accross the 3x2 ceiling joists and put a 12mm piece of plywood on top of that for the tank base. The span accross the joists (between walls) in the area I wish to put the tank is 2M. I think this will be OK as the current tank sits across 2 joists only and the new one will sit across at least 5, just needed some confirmation.