It helps to tell people a little more about your tank. Size, flow, water paremeters, how long it has been set up, etc.
Its better to find the reason why you have red slime in the first place.
Look in the Archives and thes a thread on red slime. I had in once, I didnt have a timer and my lights would stay on a long time during the day, I cut it down and it went away in about 2 weeks and hasnt came back.