Salt Water in Fiberglass Pools: Can It Be Done?

So, you’ve decided to install a swimming pool in your backyard. That’s great, but it’s just the start, and there are a lot of choices to make before you take that first swim. The size of the pool, the shape, the decking, and are you going for a custom-made concrete pool or a pre-formed fiberglass one? And if you decide on fiberglass, should it be freshwater, or can it be saltwater?

There’s no reason why a fiberglass pool cannot be salt water, and the two factors are perfectly compatible. Salt water has many advantages, one being that less chlorine is required for sanitizing, and the water is, therefore, softer and gentler on the skin and pool surface.

Not only is a fiberglass pool extremely compatible with salt water, but it’s also the best choice when compared to concrete or vinyl pools. Concrete surfaces are corroded by salt and will need to be restored, and metal-walled and -framed vinyl pools are subject to rust forming as a result of the reaction of the metal to salt. Let’s look at all the pros and cons of fiberglass and saltwater pools in order to be fully informed before making a decision.

Can Fiberglass Pools Be Saltwater – All You Need To Know

While it seems to be a no-brainer, there are always two sides to every choice, and opting for a fiberglass saltwater pool is no exception, with both positives and negatives to consider.

Choosing A Fiberglass Saltwater Pool -The Pros

There are tens of thousands of fiberglass saltwater pools already installed in private and public spaces, and there are many good reasons for this.

Benefits Of A Fiberglass Pool

  • Durability: A high-quality fiberglass pool can last for thirty to fifty years without the need to replace the lining, as is the case every five to ten years with vinyl pools, or repair and restore the pool surface, which is required approximately every ten years with concrete pools.
  • Low maintenance: The smooth gelcoat surface of a fiberglass pool will not react with the salt in a saltwater pool or with any other sanitizer or chemical. Fiberglass won’t support algae growth and doesn’t require frequent scrubbing or even brushing down.
  • Fewer chemicals are needed: Because a fiberglass pool’s smooth surface doesn’t provide a breeding ground for bacteria and algae, fewer chemicals are required to keep the water clean and healthy.
  • A fiberglass pool installation can be done in a few days, as it is pre-formed in a specialist factory and simply dropped into place. You can expect to have a fully-fledged pool area completed in about two weeks using a fiberglass pool, whereas concrete pools, conversely, can take months to build on-site and, as a result, are more expensive to install.

Benefits Of A Saltwater Pool

  • The saltwater in your pool, while containing only one-tenth the salt found in seawater, produces sufficient chlorine to sanitize the pool and keeps it at a constant level.
  • Because of this consistency, less chlorine is needed, so the water feels softer and gentler and doesn’t cause eye and skin irritations.
  • In a saltwater pool, there is no chlorine smell and no “fishy” odor associated with the production of chloramines found in chlorine pools.
  • Fewer chemicals are required, which translates to cost savings over time, as well as being safer and environmentally friendly.

Choosing A Saltwater Fiberglass Pool – The Negatives

As I’ve said, there are two sides to every coin, so what are the disadvantages of installing a fiberglass saltwater pool? There are a few.

Cons of Fiberglass Pools

  • There is only a limited number of designs and sizes available. Due to handling and shipping restrictions, the maximum size of a fiberglass pool is approximately 40 feet by 16 feet.
  • While fiberglass pools can last up to 50 years, they are liable to crack if installed incorrectly or manufactured poorly.
  • Fibreglass pools are more expensive than vinyl-lined pools and usually require professional installation.

Cons Of Saltwater Pools

  • The initial installation cost is relatively high, as specialized equipment is needed in the form of chlorinators (also known as chlorine generators.)
  • The salt cell must be replaced every five to seven years, costing anything up to $1000.
  • Salt water will damage vegetation around the pool if it comes into contact through splashing or leaks in the drainage pipes.

Is Fiberglass The Best Option For A Saltwater Pool?

Having confirmed that fiberglass pools can be saltwater, the question remains whether it is the best option compared to other types of pools.

The Vinyl Saltwater Pool

The upfront or initial costs of installing a fiberglass saltwater pool are higher than if you chose a vinyl pool but will be less than the concrete pool option. If you check chlorine levels diligently and keep them below 1.5 PPM, the liner could last up to ten years. However, there’s still the possibility of the salt corroding the metal walls and framework.

I would only suggest choosing a saltwater vinyl pool if you have a strictly limited budget, as it’s definitely the option with the greatest risk of damage from the salt. Careful maintenance, however, will reduce that risk.

The Concrete Pool Option

A strong contender for the best option, but the salt water will damage the cementitious surface and reduce the lifespan of the pool. Saltwater is up to 5 times more abrasive than chlorine water, so it’s inevitable that you will have to resurface your pool after about ten years.

However, concrete pools offer more aesthetic value, can be built in any shape or size to suit the landscape, and add more value to the home, which is the deciding factor for many homeowners.

The Fiberglass Pool Option

More expensive than vinyl, cheaper than concrete, and will last up to 50 years if well-maintained. Fiberglass pools have become more sophisticated over the years, with built-in seating, tanning ledges, and a wider variety of shapes, so in many ways make the most sense when choosing a saltwater pool.

Most importantly, if best quality, the fiberglass will not be affected by the salt, so no repair work needs to be factored into the long-term costs.


Fiberglass pools can be saltwater and offer the best option for ease of maintenance, installation costs, and longevity. Whether you’re designing your pool from scratch or wanting to convert an existing pool to saltwater, fiberglass is an excellent choice, and one which will give you a largely trouble-free pool for many years to come.