PVC sheet instead of cover glass?

[sashimimaster]

I kinda prefer acrylic over glass. It's easier to cut and don't you have to worry about shattering. I glue on some support rubs to minimize bowing. I like a slight bow so the condensation drips down the middle instead of the edges and breeds algae.

 

[Luc53]

I much prefer plexyglass for tank tops.

To get around the bowing problem, I glue some strips of plexyglass upright on top of the cover. This seems to stifen it enough to stop the bowing.

Luc