

I want to put a drainage grate around the pool for two reasons, 1. To stop water seeping down side of pool wall 2. Collect the water from surface area and store in a tank to return to pool when water evaporates as we are on tank water.
the pool area is 15 x 8 but has minimum fall over the 15m length .
need some advice as the rule of thump would require 150mm fall over that distance.