Advice on Nitrate/Phosphate problems

[Ruth]

Over time sand seems to have a tendancy to collect a lot of detrious (sp). There have been a quite a few (long) threads on it on various boards. Once the sand reaches it's carrying capacity it has a tendency to crash or release all those toxins back into the tank. I am not sure on all the technical aspects of it I just know that my BB tanks appear to be heathier than my DSB tank.