Supposed to be anything 1/4” thick the uv disburses. I haven’t seen any crazing in the acrylics. I’ve burned fish with open uv before thru a pvc with holes drilled thru it. I’ve also run open uv in the back of glass aio without issues. The light doesn’t get to the skimmer. It’s in the drop down side before the heaters.
I right. You guys make me paranoid. Lol. I don’t think it’s gonna happen cuz the bottom of the mason jar is the thickest. But anyways. I put a 1/2” piece of sacrificial acrylic between the jar and the sump panel.