Hi, Newbie Here, In Planning and Research Stage

[Aquattro]

I found that it was often exposed and created little 1/4" packets of compressed sand in each hole. It limits available space for sand dwelling critters unless you're using a lot of sand. It didn't do much for rock stability IMO, compared to many other tanks where I didn't use it. Upon removing it, the sand packed into the holes was very dark and stinky, not a healthy sand bed. I don't even quite recall why I used it, and a couple years into the tank, I wish I hadn't. Once it's there, it doesn't come out unless you empty the entire tank.
In the end, I think it adds complexity and potential issues and doesn't give any benefit to these costs.
If you really don't trust gravity to hold the rocks in place, add a small square of eggcrate to the bottom of rocks using putty or whatever.