We have just added a new Sta-rite PLD50 DE filter because the cartridge filter that came with our Endless Pool seemed undersized for our pool (over double the volume of a standard endless pool). We also have an iron problem with our well water, and sequestering agents say to backwash the filter before adding the agent. The problem is, I have read all the literature that came with the filter, and everything I can find online, and I can't find any instructions for backwashing this filter. Our installer showed us how to "backwash" by taking whole unit apart, hosing the cartridge off and reassembling, but I can't imagine that we have to go through that process just to backwash this filter, especially when the pre-purchase brochure claims that it is essentially maintenance free. Our pool is less than 5000 gallons - indoor, and the bather load is a max of two, except when the grandkids visit, maybe once a month. I have looked and looked, though, and there doesn't seem to be any kind of a backwash valve or setting on the filter, and as I said, nothing I can find in the literature. We do have a continuing iron problem, though, so I don't want to keep adding sequestering agents if they are just releasing metals in the filter back into the pool. It's a very expensive filter and it is very frustrating that the product manual is so vague. Our installer is no help. He has already given us bad info on several counts. Told us to put Vaseline on the O-ring, for instance. Fortunately, I read the literature before doing so. Does anyone have experience with these filters???