Quote Originally Posted by badflash
If your growbed is quartz gravel, you'll have all the silicone you need.

Also, the thing about airstones not putting oxygen in the water is nonsense. If you use an airstone in a still tank the fish will swim around happily. Turn it off and watch them come to the surface and gulp air.
I've noticed that too, like I said, you're welcome to take some of his 'tips' with a grain of salt