A lot of people do this, thinking they are adding bacteria..... etc. In reality, they are just adding dirty water with little benefit. It's what's in the rock, and surrounding each sand grain that has what you want.<a href=showthread.php?s=&postid=8400354#post8400354 target=_blank>Originally posted</a> by jjb81speed
what are the possible negative effects on my tank that can occur by this? anybody else try this before?