Anyone who has spent a summer in Tracy knows the wind. It builds through the afternoon, funnels down off the Altamont Pass, and keeps moving well into the evening after the heat breaks. It is pleasant on a patio and hard on a pool. The air coming over the hills carries fine grit with it, road dust, dry field dust, and the powder that lifts off open ground every time that ground gets worked. There is less leaf litter here than in the older river towns, but far more suspended solids, and almost all of it ends up in one place. Your filter is the last stop for everything the wind drops in the water, and that is why filters in Tracy load up faster and give out sooner than the same filter would in a sheltered yard.

The other half of the picture is water chemistry. San Joaquin County water is hard, and calcium and alkalinity both run high out of the tap. Every time a pool loses a few inches to evaporation and wind during a hot week, the minerals stay behind and the water gets a little harder. That scale settles into cartridge pleats, coats sand grains, and stiffens DE grids, and once it does, no amount of rinsing brings the flow back. A filter that is being short cycled by grit and glazed by hard water at the same time will not last the ten or twelve years the brochure suggests.

Nevergreen Pools handles filter installation & replacement in Tracy in partnership with Vintage Pool Service, a Central Valley company that has run pools out of Manteca and along East Yosemite Avenue for years and knows what these systems do in this climate. Most of the homeowners we work with in Tracy commute over the pass or down the freeway and are not home while the work happens, so what follows is a plain walkthrough of what we do, in what order, and what you will find when you get back.

Reading the Filter Before Replacing It

A filter that needs replacing usually says so through pressure first. Every system has a clean starting pressure, the number on the gauge right after a fresh cartridge, a full backwash, or a new DE charge. When the gauge climbs eight to ten pounds over that number, the media is loaded and flow has dropped. What matters is not that it climbs, because it always does, but how fast. If a cartridge that used to run three months in Tracy is now hitting cleaning pressure in five weeks, the pleats are either packed with fine dust that will not rinse out or glazed with calcium. Both are terminal for the element.

Before we quote a replacement we open the tank and look, because the same symptom has several causes and only some of them call for new equipment. What we check on site:

• Element condition. Collapsed or splayed pleats, torn fabric, broken end caps, and DE grids with worn cloth or split manifolds.
• Media age and channeling. Sand that has cemented into clumps or worn round loses its bite, and water cuts a channel straight through it.
• Tank and valve. Cracked laterals, a chewed multiport valve spider gasket, a weeping backwash line, and clamp bands that have corroded.
• Actual flow. What the pump is really moving at each speed, which on a variable speed pump is often nothing like what the panel display suggests.
• Filter area against that flow. Square feet of media versus gallons per minute, which is where most undersized systems get caught.

That last item decides most jobs. A filter is rated in square feet, and the more area you have relative to the flow through it, the slower the water moves through the media, the finer the particle it catches, and the longer it runs between cleanings. In a windy town the right move is almost always to go up in size. Where the original installer matched a small cartridge to a small pool, we would rather see a much larger element on the same pad, so the filter runs a full season on Tracy dust instead of a month.