Join Date: Sep 2018
Location: On a well in Illinois
I can't answer your question but I would suggest that if you use acrylic getting a smaller piece and testing it out to see of it holds shape against water. I bought a sheet and made a custom lid for my 10 gallon. It developes a slight bow after about a week. In my case it's not very noticable and easily correctable by ocasionally flipping the lid, but I imagine that this could be greatly pronounced in your project.