Nylon Fasteners

[mike31154]

If the goal is to raise rock off the bottom, have you considered using large diameter pvc pipe? That's what I've used. Drilled some extra holes around the sides to allow burrowing critters to do their thing & minimize the chance of total stagnation. Actually I used black ABS which is buoyant, so a bit of a challenge to keep down while positioning the rock if you're doing it with water in the tank. Anyhow, I'm sure the white stuff would work also & it's easy to source. Next time I do this I'll probably cut the pieces into half (semi-circles) & silicone them to the bottom. Will take a bit of fiddling about to get it right I'm sure, but no more work than drilling into rock & less messy.