Can Any Pool Be a Salt Water Pool?

Most pools can be converted to salt. The pool itself rarely decides it. The real question is which materials in and around the pool tolerate water that is slightly salty, and how you protect the ones that do not. Vinyl liners, per the liner maker we cite, last as long as they would with chlorine. Porous stone and concrete decking need a sealer.

What a salt conversion actually changes

A saltwater pool is a chlorine pool with a different way of adding the chlorine. You dissolve salt in the water, and a salt chlorine generator turns some of it into chlorine as water passes through the cell. The cell gets plumbed into the pool’s equipment, which our guide on how to install a salt cell walks through. Nothing about the pool shell has to change.

What does change is that the water now carries dissolved salt. Keep the scale in mind. Salt pools usually run around the 3,200 ppm one manufacturer’s manual calls ideal. NOAA gives average ocean salinity as “about 35 parts per thousand”, or about 35,000 ppm.

The comparison: 3,200 / 35,000 = 0.091, so pool water is about 9% as salty as the ocean. That is enough to matter for porous stone over years. It is not seawater.

It is still a lot of salt by weight. One pound per 1,000 gallons raises salinity 120 ppm, so pounds needed = (gallons x ppm needed) / 120,000. Taking an 18,000 gallon pool from no salt to 3,200 ppm is (18,000 x 3,200) / 120,000 = 480 lb. Most backyard pools hold 10,000 to 18,000 gallons, as the guide to average pool size in gallons shows. The pool salt calculator does this for your own numbers.

Surface by surface

Here is what our sources support for each material, and where they say nothing.

Vinyl liners

Latham says that with a saltwater pool you can expect your liner “to last just as long as it would in a chlorinated pool”, which it puts at 8 to 12 years. Worth knowing: Latham makes liners, so it has an interest in liners looking durable either way. We go further into this in how long a saltwater liner lasts.

Gunite and plaster

Yes, and this is the oldest fight in salt pools. A gunite shell with a plaster or aggregate finish is cement, and the claim you will hear is that salt eats it. A fiberglass pool manufacturer’s blog says salt water can be up to 5 times more abrasive on plaster than traditional chlorine water and that salt gradually wears away the cementitious finish. That is a builder blog with a competing product to sell.

The engineering literature points elsewhere. In reinforced concrete, the penetration of chloride ions is the major contributing factor for inducing corrosion of the steel reinforcement, and the cracking and spalling that follow come from expanding rust, not from chloride dissolving the paste. Rebar in a gunite shell sits behind inches of concrete and plaster.

The substantive argument is water balance. Aggressive water etches cement with or without salt in it: low LSI issues include etching and pitting of cementitious surfaces and tile grout, and water short of calcium carbonate “finds and takes it from anywhere it can”. A salt cell drives pH up continuously, so see how to lower pH in a salt water pool.

One firm rule: on new plaster, wait. Start-up guidance says for saltwater pools, do not add salt within the first 30 days, and one finish manufacturer’s care sheet asks for at least 28 days, warning that salt left on the surface may scale, stain or discolor it. Build that into any conversion to salt water.

Natural stone and concrete decking

This is where salt does real damage. Travertine Mart describes efflorescence, where “salt water absorbs into the stone’s pores and leaves behind a white, chalky residue”, and spalling, where “pits begin to form in the travertine because salt water crystals are trapped beneath the surface of the stone.” Its example is unsealed natural travertine coping that showed spalling after 2 years of daily exposure.

The fix is sealing. Travertine Mart recommends a water repellent, impregnating sealer, which it says gives “reasonable protection for 5-10 years.” Concrete and pavers are porous too, so the same logic applies, though our sources give no resealing interval for concrete. Our page on sealing concrete around a salt pool covers the details.

Metal walls, heaters and other equipment

We do not have a source we trust on how salt affects metal wall above ground pools, heaters, ladders, lights or specific pumps and filters. So we are not going to guess. The manufacturer of your pool or of each piece of equipment is the authority here. Check the manual or warranty terms for any mention of salt or saltwater chlorine generators before you convert. If a manufacturer excludes salt, that settles it for that item.

What conversion costs

Two sources give numbers, and they measure different things.

These do not line up neatly. HomeGuide’s whole conversion range starts well below River Pools’ price for the generator by itself, and River Pools’ article is about inground pools, so its figures reflect that market. Neither is wrong. They describe different equipment and different jobs. River Pools also says that overall, “a saltwater pool costs about as much as a traditional chlorine pool”.

For a closer look at pricing, see cost to install a salt water pool.

A short checklist before converting

The full switching decision

Whether any pool can be a salt pool is one question. Whether yours should be is a bigger one, covering running costs, maintenance and how you like the water. Our salt water pools hub pulls that decision together, and the salt cell guides cover life after the switch.

Where to go next