I got one you can buy because I dont use it, and like everyone else on this thread says... you dont need it. But, if you really want it, i guess you can buy mine. Just keep in mind, i add about 2 quarts of ro top off a day without the top on.
I might take you up on the offer. I think I would keep it on when the lights are off, I don't want my cat going for a swim in there while I'm sleeping...how much are you looking for on the top?