As I have said on another forum. I think I found my favorite tank cleaning tool. A bucket vacuum to conduct my water changes. This thing sucks up all the GHA that I have been battling. All I did was buy a mini attachment kit and made a long hose out of some tubing. The kit has a stiffer brush that works perfect. Just turn on vacuum and brush all of that unwanted GHA of of your rocks. I like the float on the vacuum that prevents water from shooting out of the exhaust.