Pool filter cleaning in Los Angeles

All three, and each is a different job. A cartridge comes out, gets stripped down and soaked overnight. A DE filter has its grids pulled and washed, the manifold checked while the tank is open, and fresh diatomaceous earth charged back in through the skimmer — skip the recharge and the grids blind off within a week. A sand filter is backwashed in service, and every five to seven years the sand itself is replaced: the grains round off with age and stop catching anything smaller than gravel. Hayward, Pentair and Jandy tanks all open the same way; the clamp and the tank O-ring are what differ, and the O-ring is what floods the pad when it is reused one time too many.

A hose first, to move the loose debris, then an overnight soak in a proper filter cleaning solution: a degreaser for sunscreen, body oils and pollen, and an acid rinse afterwards only if the water is hard enough to have left calcium in the pleats. Dish soap is the usual home remedy and the wrong one — it rinses badly and the pool foams for weeks. Acid on its own is worse: it sets the oils into the fabric instead of removing them.

On the gauge, not on a schedule: at roughly 8 to 10 psi above the clean reading. In practice that is three to four cartridge cleans a year on a typical Los Angeles pool, and every six to eight weeks under heavy Foothill tree cover.

The gauge is the honest answer. Weak jets, a slowed cleaner, haze and a heater cutting out are late symptoms. One exception: if pressure is low and flow is poor too, the restriction sits before the filter and cleaning it changes nothing.

Yes, and on a cartridge filter most owners should. One rule outranks the rest: cut power to the pump and open the air relief valve until the tank is depressurised before touching the clamp band. Not DIY: DE or sand in the pool, or high pressure right after a clean.

Cartridges are made to be cleaned and reused, typically for two to five years, and DE grids last until they are physically damaged. Sand is different: the grains wear round and stop catching fine debris. A cartridge is finished when its pressure after a clean no longer returns to the old baseline.

Acid is for chalky calcium scale only, and never before degreasing: on a greasy cartridge it sets the oils into the fabric. When called for, use it well diluted, always acid into water, as a dip of minutes rather than an overnight soak. Never let it meet chlorine, and check your manufacturer's guidance.

Flow falls, and everything downstream of it suffers. Chlorine demand rises, a variable-speed pump eats into the saving it was bought for, and a gas heater starts locking out. Left through a warm spell the pool goes green, and recovery starts at $349 against $149 for the clean that would have prevented it.

A one-off clean is $149 for a cartridge filter, $179 for DE and $199 for a sand deep clean. On a pool we already look after, two deep cleans a year are inside the monthly service price, and any clean beyond those two is $119, $143 or $159 by filter type. Replacing sand media starts at $349 plus the sand.

In two stages, in this order, or it does not come clean at all. Hose the pleats apart first, fanned open and worked down each fold, rather than blasting across the top where the dirt only moves sideways. Then soak it overnight in a degreaser, because the grey in a Los Angeles cartridge is mostly sunscreen and body oil and no amount of water pressure shifts that. A short, well diluted acid dip comes last and only for chalky scale. A cartridge left two years often takes two soaks, and some of them never come back to their old pressure.

The cartridges are the short-lived part: two to five years here, and sooner on a pool run hard or on one cleaned with a pressure washer, which drives the fibres apart. DE grids last until the fabric tears, often eight to ten years. Sand goes five to seven before the grains wear round and stop catching anything fine. The tank outlives all of them — what actually fails on it is the O-ring and the clamp band, which is why both get looked at every time it is opened.