Common questions,
honest answers.

Most guidance says one to three parts per million of free chlorine. That's a useful range for the average pool, but it isn't the whole answer. How well chlorine actually works depends on pH and on cyanuric acid, the stabilizer that keeps chlorine from burning off in sunlight.

A pool at 3 ppm chlorine with high cyanuric acid can be less protected against algae and bacteria than a pool at 1 ppm with low cyanuric acid. The better metric is free chlorine in proportion to your stabilizer, roughly 7.5 percent. If your stabilizer reads 50 ppm, you want chlorine around 4 ppm. If it reads 30, around 2.5 is fine.

It's a small piece of math, but it's the reason two pools "at the right level" can behave very differently.

On top of all that, chlorine gets used up constantly. Between UV from the sun and people swimming, a pool can easily burn through three or four ppm in a single day. If you're sitting at 5 ppm on a Thursday and the kids host a swim party Saturday, there may be no chlorine left by Sunday. If your service comes Thursdays, that's enough time for algae to take root before they're back.

The fixes vary. Stabilized chlorine (tablets) keeps a steady dose feeding in, but tablets also add cyanuric acid, so they need to be used carefully. A saltwater chlorine generator keeps the pool dosed continuously, a little at a time, which avoids the peak-and-crash pattern entirely. And if you have a service, tell them about the swim party ahead of time. We leave an extra jug of chlorine with our customers when we know company is coming, with simple instructions on how and when to add it.

The instructions on the chlorine jug assume your pool is in chemical balance. If it isn't, and most aren't quite, chlorine gets partly consumed by side reactions and doesn't kill algae effectively. The four most common reasons algae returns despite chlorine:

Cyanuric acid is too high. Above about 80 ppm, chlorine becomes sluggish. This is the single most common cause, usually because the pool has been chlorinated with tablets, which add cyanuric acid as they dissolve.

Phosphate levels are high. Phosphates are algae food, and they enter the pool from rain, fertilizer, tap water, and bathers. Without removing them, you're fighting an enemy that gets fed every day.

Circulation is poor. Algae loves dead spots. Steps, behind ladders, and corners are usually the first sites of a bloom.

Brushing is irregular or skipped. Brushing dislodges the early biofilm before it becomes visible. It's the single most effective thing a homeowner can do.

Weekly, in almost every case. In San Diego, where pools are open year-round, weekly is the rhythm that keeps chemistry stable, surfaces clean, and equipment lubricated. Every-other-week service is sometimes offered as a money-saver, but the math rarely works out. Chemistry drifts further between visits, more chlorine gets dumped to catch up, and the equipment runs harder.

Different, not easier. Salt pools generate their own chlorine through electrolysis. That's the real appeal. What you still need to manage: pH, which drifts steadily upward on salt pools, cyanuric acid, and the salt cell itself, which scales and degrades over time.

And the salt. You add salt to the pool when it runs low, which happens slowly with normal use, or faster if there's a small leak somewhere. On a typical pool, we add eighty to a hundred and sixty pounds of salt twice a year.

Is the water "softer"? A little. Most of the smoothness people associate with salt pools comes from cleaner overall chemistry, not from salt itself. For scale: a salt pool runs at roughly ten percent of the salt concentration of the Pacific Ocean, so no, you can't taste it.

Because the work varies enormously. A weekly visit can mean a "net and jet" or "splash and dash" (the pool version of the landscaper's "mow and blow"): five to ten minutes of skimming, a scoop of chlorine, on to the next pool. Sometimes that's all a pool really needs that week, but doing the job right usually takes longer.

A proper chemistry test drawn from a foot below the surface, hand-brushed walls and steps, lubed O-rings, an inspection of every piece of equipment, and treatments planned around what the water is actually telling you, all of that takes time. So does training the technician to understand the work in the first place. There's a reason an oil change costs different amounts depending on where you take it. Most of the time, the higher price is warranted. Sometimes it isn't. In general, you get what you pay for.

When comparing quotes, the question to ask isn't "what does it cost" but "what do you do at every visit, and how long does it take." The honest answer will tell you what you're really buying.

It depends. With chemistry held in balance, filters cleaned on schedule, and equipment serviced per the manuals, the following are reasonable expectations. How hard the equipment is run and how many hours a day it cycles can shift those numbers either direction.

Pumps, ten to fifteen years. Filters, fifteen years or more, with internals replaced or rebuilt on occasion. Salt cells, around five years. Gas heaters, fifteen to twenty-five years. Plaster, ten to fifteen years. Pebble surfaces, twenty or more.

Hard water and unbalanced chemistry shorten every one of those numbers. We've seen heaters fail at two years and salt cells at six months, almost always because the water had been running scaling or aggressive for a long time before anyone noticed.

For a typical residential pool, the short list is: a sanitizer (chlorine in some form), a pH adjuster (muriatic acid most often, sodium bicarbonate going the other direction), a stabilizer (cyanuric acid) to keep chlorine from burning off in the sun, and a calcium adjuster only if your fill water is unusually soft. In San Diego the opposite is the issue, so calcium adjusters are rarely needed.

Beyond that, a good weekly service adds enzymes to break down body oils and lotions, and a phosphate remover to starve algae of its food source.

We don't endorse brands, and we won't send you to a specific store. The product matters less than the dose, and the dose depends on numbers you can't read off a test strip. That's the harder problem.

Eventually, yes. Total dissolved solids and cyanuric acid build up over years and can't be removed by any other means. The common recommendation in San Diego is to drain and refill every five to ten years, depending on use, rainfall, and how hard the local water runs.

That schedule comes up faster than people expect because our tap water averages around 275 ppm calcium hardness. Every time water evaporates, the calcium stays behind, so the pool quietly drifts toward scaling chemistry whether anyone is watching or not.

An alternative to draining is reverse osmosis treatment, which removes the dissolved solids while keeping the water itself. It costs more than a fresh fill but uses far less water, which matters in drought years.

One last thing: in San Diego, draining to the storm drain is regulated. Water has to be dechlorinated, pH-adjusted, and free of algae before it leaves your property. A good service handles that for you.