Bencc's idea thing sounds really good...however, I just added some semi-wet live sand I made through the PVC pipe and it worked like a charm. If you're patient adding just a little at a time, and don't mind the mess all over you (wear gloves)...it worked out so well that I had only one hour of cloudiness...and that was because a few times some sand slipped out of my hand, missed the PVC and went straight into the tank. Just turn the waterflow off in your tank, and keep the pipe low to the bottom of it....