Sand bed questions

[kien]

That works, and I've seen a few people do that. You can also put down a sheet of acrylic under your heavy rocks/structures (that's what I do). I did the egg crate thing once and what ended up happening was the flow in that are kept clearing enough of the sand to expose the egg crate.. argh! It was annoying. I get that in my 150 reef as well ( the clearing of sand from powerheads) but the exposed acrylic isn't so bad because it just gets encrusted with coraline and blends in nicely.