When it run wet it pulls brown tinted water. When it runs more dry, it pulls like brown green sludge that just accumulated around the rim. I don’t know how to control whether it runs wet or dry... it just decided a what it wants to do lolIn that case is it pulling dark colored or even tinted water? If so that’s going to be a huge help in the fight on the algae. Can also reduce the white light and use mostly blue if possible. Hair algae doesn’t use the blue side of the spectrum as well as coral does.