I I thought that I had to change out 150 gallon a day between my sulfur denitateor and my drip system because I have a very high bio load and I feed 3 times a day and my Nutrient levels climed constantly no big spikes or anything but that brings me to Friday when I found the seem in my sump was leaking it was hard to see because I has my 40 gallon QT tank in front of it, so moved the QT tank and started to drain the sump got about half the water out before I realized that the bottom 3 inches or more of the sump was all detritus. The tank has only been up about a year and I use filter socks. I could not believe how much there was, I am going to look into it and see if there is anything I can put down there to eat it, I also bought a small wavemaker to help keep it suspended so it don't build up. I guess most people vacuum it out when they do a water change? I already see a difference that my denitater is catching up and reducing the nitrates I use to have to add water to every 6-8 weeks.