So if we can lets move past the cons of a solid lid and yes I know a screen or an open top is advisable. Assuming I choose to use a lid, does anyone have any experience with petg? if so, how thick did you need it to be to stay rigid over the tank? and if glass, same question. I just get the feeling ill break it at some point but don't want the bowing of acrylic. I read somewhere that petg doesn't absorb water like acrylic thus doesn't really bow.