Old water? Change it without emptying the pool.

When the water itself is the problem.

Pool water in North County gets old. Every gallon that evaporates leaves its minerals behind, and every gallon of Vallecitos tap water you add brings more in. After four or five years the calcium hardness is past 400 ppm, the stabilizer is past 100 from years of tabs, the total dissolved solids are somewhere north of 2,500, and the pool is scaling tile, eating salt cells, and going cloudy in weather that never used to bother it. Chemistry can't fix that. Only changing the water can.

There are two ways to change it. The old way is a drain and refill: pump the pool out, refill from the hose, and start over with fresh hard tap water that's already halfway to the same problem. The better way for most North County pools is reverse osmosis, where a mobile unit parks in your driveway and cycles the water through membranes that strip calcium, stabilizer, salt, phosphates, and metals while the pool stays full. You keep roughly eighty to eighty-five percent of the water, the pool is never empty, and you finish with water cleaner than what comes out of the tap.

Which one your pool needs

We test first and tell you straight. If your calcium is high and everything else is close, RO is usually the answer, and it's the only good answer for a pool with a hydrostatic risk, a high water table, or a surface that shouldn't be exposed to the sun for two days. If the stabilizer is the main problem and the pool is small, a partial drain can be enough. If you're converting from salt to chlorine or the water is beyond what membranes can handle in a day, a full drain and refill is the honest call. We'll also tell you when a drain isn't safe — plaster left dry in a July Santa Ana cracks, and an older pool in a wet spring can lift.

How an RO day goes

The unit arrives in the morning, hoses go to the pool, and it runs for the day, sometimes into a second morning on a big pool. There's a small wastewater stream that goes to the sewer cleanout. When it's done we re-test, bring the water back into range — it comes out too pure to leave alone — and put the numbers on your report. After that, the weekly service keeps it right, and you shouldn't need to think about the water itself for years.

We do RO and drain-and-refill work across Vista, San Marcos, Escondido, Carlsbad, Oceanside, and Rancho Santa Fe, and quote by pool size after a water test. Ask us about it if your salt cell is scaling faster than it used to, your tile line is white no matter what, or your pool has been on tabs for more than a few years.