Swimming Pool Repair Tips
CARTRIDGE SWIMMING POOL FILTERS
"How do I Backwash my Cartridge Filter? A trick question. There is no backwash valve on a cartridge filter because today's pool filter cartridges aren't built for reverse flow. Instead, the pump is shut off, air bleeder opened, lid removed, cartridge removed, hosed thoroughly Top to Bottom, and replaced. It's a bit of a pain to do, but hopefully the filter is sized so that it's a 1-2 x per year job. Another advantage is that cartridge cleaning doesn't waste as much water as backwashing.
Soaking the cartridge in a TSP or similar solution prior to hosing will improve your cleaning. Do not use TSP if you utilize Baquacil or Soft Swim for sanitation. There are also commercially available cartridge cleaning solutions that will help dissolve certain oils, salts and other minerals.
Use of a clarifier or Chitin product like Sea-Klear is a great help to a cartridge filter. Some people also increase the filter efficacy by adding a small amount of synthetic filter aid powder (1-2 cups) through the pool skimmer. DE powder is not recommended by most manufacturers, as it can clog the pores of the cartridge. (but secretly, we sometimes use a little bit, on cartridge filters that are undersized, to help improve filtering ability of the pool cartridge.
Disposal / replacement of the cartridge, its difficulty in maintenance (no backwashing) and its relatively low efficiency are the reasons I don't recommend these filters for use in most larger swimming pools. But for pools under 30,000 gals. there are some nice filters like the Hayward C-4000 that can really be a great filter.
Filter Cartridge Replacement: Right off the shelf for $40-100, depending on its size. No professional labor needed.