Detailed articles about adding DE to sand filter, but no equivalent for cellulose fiber. From my reading on TFP threads, users of CF seem to have resounding success. Given that CF can be backwashed right onto the yard & less legal/environmental considerations, should TFP consider a pivot towards suggesting CF instead of DE as the primary suggestion for adding to sand filter? I will be helping with an undersized sand filter swamp in a few weeks and am tentatively planning to use CF to speed up the end stage SLAM water clearing, since last year this pool took weeks to achieve perfection, despite a deep clean. Are there any hesitations with CF that are not there with DE? Can it be added through the skimmer as well or must it be sprinkled inside the sand chamber? Thanks for the info and, of course, all the consideration that goes into articles and stickies. They have helped me and have helped me help others. All you TFP contributors are the best and worthy of all the praise you receive and more!