J_T link said:
[quote author=Chewy link=topic=4951.msg46566#msg46566 date=1364583976]
sweet tys guys
Do some reading before you use it on the bottom of a tank. There are some negatives. Nitrate factories are one worry.
[/quote]
That was my first thought, very similar to an undergravel filter, you'd end up with all sorts of nasties filtering down through the eggcrate. I placed my rock directly on the bottom of the tank and then added the substrate so the rock wouldn't shift.