I removed most of the rock to get rid of all other unwanted pests that I had picked up over the years before putting up this 240(most is in fresh h20), any aptasia, predatory stars over taking sponges and I am sure there is more. also I removed all of the sand as I learned I did not really like the way it looked, so all in all I learned that it was not the way I wanted and I wish I would have been able to see this before I set it up but I guess sometimes you have to see it to know. I just thought I would take care of all of the problems at once the ICH the pests and the sand I hope I like it when it is all done. It is my final upgrade so I might as well do my masterpiece right.