Sump cover

[Keith A.]

I built my own sump and it has been running now for about one week. I used a piece of acrylic (1/8 of an inch thick) to cover the top of the sump to minimize evaporation. However, I'm noticing it's starting to bowe or sag in the middle pulling the corners up. Is there anything that can be cut and used to put on the top of a sump to reduce evaporation?

 

[chagoi]

I did the same thing. Going to attach a aluminum brace to the outside/top.