Im posting this for a friend of mine, he has a horrible red slime algae problem. There had been a little bit, then within a few days just exploded. He did just add a new fish which died within hours of taking it home, his params where perfect. My guess is the fish just wasn't healthy in the first place. We just added purigen and changed out the chempure elite, I'm not sure what else to have him do other than siphon most if it out. He did that and it came back even stronger, any suggestions???