I'm debating on draining my sump and removing some five year old miracle mudd type material along with about an inch and a half of ? (Waste maybe) that's built up over the years. In that section of my sump there is a small ball of cheato and a mangrove the same age of the tank. The main system is sps dominant with about 15 chalice and brain. This is the thing though. The tank is healthy with no problems. At this point the tank runs itself. My concern is that one day this collection in my sump may cause me to loose some sensitive corals due to some sort of release of phosphates or such. Also I would like a little more color in some of my corals. Of course when I test the system everything is good. Also I plan on leaving the tree and the cheato. What do you think? A few members of my local club say leave it and I'm leaning that way, but I feel like its something I should do. Also I know I was suppose to change some after a year or so but you know... so what's my pros and cons? Thanks for reading.