Some of your float switches you wouldn't want them to fail as you would end up wit a lot of water flooding the place, my double garage here flooded a year ago and I'm just getting to it now ,a bit of dirt covering the concrete but I haven't noticed anything damaged as the water was only a few inches high.
That casting cement sounds good Norm , is it a cement mix product or a two part epoxy ? ,has it got a name on the packet as I might try some.
