Are Salt Water Systems Bad for Concrete Pools?
Close your eyes and picture the sidewalk on your street.
I myself live on an ominous back road—no sidewalk or concrete, just loose gravel and abandoned houses. But it branches off the main street, which is paved and has a sidewalk. Fancy.
This sidewalk features trip hazards and aesthetic issues: multiple cracks, salt stains, little holes and etching, and (bonus) a set of footprints from a small dog.
Concrete has its own set of issues, but let’s think about those salt stains and etches for a moment. That’s just from the occasional weather maintenance, like the trucks that spray salt all over the road and the sidewalks (and your car if you’re driving behind them).
Water in a concrete pool wears at the plaster all day every day. Now add a salt chlorine generator to that mix. Salt + water + concrete. See how that might be an issue?
Things you should know (and that we’ll explain):
- Whether salt water damages concrete pools
- How to maintain a salt water system
- Whether salt chlorine generators damage vinyl liner or fiberglass pools
Does salt water damage a concrete pool?
Are salt water systems a problem for concrete/gunite pools? Not in the sense that there are thousands of concrete pools failing across the country. Whew.
But does it shorten the lifespan of the pool finish? We believe it does.
Big ol’ caveat: too much chlorine or salt in ANY pool will damage the pool and equipment.
However, on top of that, we think salt water does further shorten the lifespan of a plaster finish (or any cementitious pool surface) specifically. Common sense—think of what salt does to a concrete sidewalk.
Salt water can be up to 5 times more abrasive on plaster than traditional chlorine water. Translation: you'll need to resurface the pool that much faster, which costs a pretty penny.
Salt gradually wears away at the cementitious finish. It's worst with plaster but a little better with aggregate. (Tile surfaces aren't so affected because they aren't made from cement.)
Unrelated but also uncool: If salt sits on the pool surface without dissolving, it can stain the surface in minutes.
How much will salt shorten the lifespan of a concrete pool’s surface? We don’t know exact numbers because salt systems have only been popular for 5–8 years. As I say when guiding my friends through online dating: we need more data.
Factors for salt system maintenance
Sometimes people will advocate salt chlorine generators as no-maintenance. But honestly, there’s no such thing.
The main benefits to saltwater pools:
- Lower annual cost
- Softer water
- Not having to lug around giant buckets of chlorine
Note that “zero maintenance” is not on that list.
Remember that a saltwater pool is a chlorine pool. They both use chlorine to keep the pool clean. The difference is in how you put the chlorine in the water.
So just like with a regular chlorine pool, you have to monitor the water chemistry regularly.
Two big things to monitor:
- Amount of salt
- Chlorine levels
One big factor is the level of salt that the pool owner maintains.
If you keep your salt at the high end of the spectrum or off the charts, it will react with the surface faster than if you keep it at the medium to low range.
Remember, too much salt in any pool is a huge no-go. Don’t do it.
With a salt system, you really, really, super have to keep an eye on your chlorine level.
The majority of surface issues in salt pools are due to neglect. The water’s clear and you don’t smell the chlorine, so you’re under the impression that it’s okay. There’s little external evidence to suggest you need to check things out. However, the chlorine levels could be five or ten times higher than they should be, and you’d have no idea.
The unfortunate reality is that most salt pool owners neglect their pool by allowing their chlorine levels to get too high. Don't do it, my friend.
Properly maintain your salt water pool, and you’re good to go. It'll stay extra easy to manage— just like it’s easier to do one load of laundry a week rather than letting it pile up for a month and doing four loads in one day. Not that I’ve ever done that, of course.
Do salt chlorine generators damage fiberglass or vinyl liner pools?
We're going to assume you’re taking care of your pool and watching your water chemistry.
Remember, too much chlorine/salt in ANY pool will damage the pool and equipment.
Vinyl liner pools and salt water
The salt doesn’t really affect the liner of the pool.
If you have polymer wall panels, the salt won’t affect them either.
However, if you have metal wall panels, beware. The liner will eventually leak and corrode the metal panels, which is the structural support of the pool. Salt water can easily sneak through cracks or edges of the liner and wear away at the metal. The wall panels can rust badly, even all the way through if it continues long enough.
Fiberglass pools and salt water
To the best of our knowledge, salt water systems don’t have any adverse reactions with the gelcoat surface of a fiberglass pool.
While the shapes and sizes are less customized, most people can find a model that's perfect for them. They’re super durable and low-maintenance—not to mention pretty!
Want more info about pools?
River Pools operates through independent installers. Get in touch with one in your area today to begin your pool journey!
If you’d like to learn more about the different types of pools, check out our comprehensive ebook "Comparing Fiberglass, Concrete, and Vinyl Liner Pools in the Modern Age.” It discusses cost, design, durability, installation… basically any aspect you’ll want to compare if you make a big pool decision.
You can also check out all our blog articles about maintenance for any other issues you may encounter. We want to help you make the most of your pool!
Editor's note: This article was updated on September 13, 2023.