The top is completely covered, but I may try covering some of the holes as ARamos suggested (thank you!). There's two rows all the way around, maybe I got too gung ho with that. Not much I can do about the height though. I got that tub because it locks down really tight and I'm hooked on the extra security, but they don't make shorter tubs of this type. Just smaller.

His substrate is technically paper, btw, Carefresh is recycled paper that's been bleached to death more or less.