Oops, my bad... i misread it as rodi container... yeah, i would hit up someone with ties to advanced acrylics... bomb stuff... jimmy would be a good start...
apparently that is normal. I only learned of that afterward. That is why nice sump systems like the dreambox dont use acrylic for their removable lids, they use a different plastic that will not warp. Perhaps in the future AA will utilize this better material on their lids.
I think from US plastics you can get 55g rectangular drums that also would do an awesome job and I think they are only like 150 bucks. 55g of top off water? heck yeah, only have to fill it once a month! Just make sure your ATO doesnt get stuck on....