11-19-2015, 10:16 AM
I initially used a 24" diameter exercise ball that I got from WalMart for $10 but it was too big. The shade cloth fits very well and is pulled tight like a trampoline by bungee cords around the perimeter. The larger ball would stretch the cover and then it would sag more when the level was lower. I replaced it with an inflatable plastic ball also from WalMart that cost $1.99. It lasted a couple of years until I upgraded my floating intake. I now use a 24" x 24" x 1" piece of pink foam from Home Depot. When the tank is overflowing as it is right now you can see the outline of the square of foam under the mesh. As soon as it stops raining the shade cloth drips dry, gets lighter, and lifts off the foam. Granted my cover fits very well. I often lay out clean laundry on it to dry.