Salt Water Pool Conversion: A Simple 4-Step Guide

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Let’s face it, having a pool is great, but almost every pool owner would love to save some time and money on maintenance.

That’s why more and more people are switching to salt water pools. In 2018, about 35% of the pools in the United States were sanitized with salt, up from less than 14% ten years ago.

But is salt water just a trend? And is it as great as everyone says? Let’s find out.

What is a Saltwater Pool? 

A salt water pool has a salt chlorine generator in it. The generator filters salt out of the water, passes it through an electrode cell, and converts the salt into pure chlorine. So it isn’t that salt water pools don’t have chlorine in them, it’s just that you don’t have to buy or add chlorine. You just have to make sure there is salt in the water to keep the generator functioning.

This is important because the chlorine traditionally added to fresh water pools creates chloramides, those excess compounds that make a pool smell like chlorine.

The truth is, as fresh water chlorine breaks down in a pool, it produces hypochlorous acid, the compound that cleans the pool, but also chloramines, which don’t do anything useful in a pool, and can smell bad and irritate the skin and eyes. 

But, through the electrolysis action of a salt chlorine generator, you simply get hypochlorous acid, and therefore clean water, without the irritation of the chloramine byproducts. 

Quick Facts About Saltwater Pools

  • Saltwater pools have about the salinity of tears, about 1/10 the salinity of sea water (but you still shouldn’t drink it)
  • Another byproduct of a salt chlorine generator, sodium hydroxide, naturally raises the pH level of the water, preventing it from becoming acidic
  • When the water is correctly pH balanced, acids cause the water to naturally restore the salinity levels. This means that you don’t need to continually add or monitor salt levels once you are at the correct salinity for the first time
  • Because the salinity of a salt water pool is similar to the level in our own bodies, it doesn’t sting or irritate the eyes 
  • Salt water pools are preferred for people with asthma and allergies, because they don’t have irritating chloramines
  • Salt water will corrode metal, and shouldn’t be used in pools with metal walls, or handrail, ladder, and other pool features that have metal components or anchors. 
  • Salt is abrasive on the inside of pool shells lined with concrete, gunite, or plaster

Why Have a Saltwater Pool? 

More and more people are converting to salt water, for big and small reasons. Some of the most popular are: 

  1. Easier maintenance. While salt water pools cost more to convert and set up, they require fewer chemicals and are easier to keep balanced over time. 
  2. No chloramines. Chloramines irritate the eyes, skin, and often the nasal passages when they are breathed in. Some people suffer from asthma or allergies that make them want to avoid chloramines. 
  3. No bleaching. Salt water pools don’t bleach or damage the fibers in swimsuits, and don’t turn blonde hair green. 
  4. Softer water. The water in a salt water pool feels silky and soft to the touch

The Downside of a Salt Water Pool

With so many great reasons to have a saltwater pool, there has to be at least one drawback, right? And there is. Expense. 

  • The initial purchase of a salt chlorine generator and pool conversion costs about $500 – $2500. 
  • Salt chlorine generators have a salt cell inside, which can last for 3-7 years and costs about $700 – $1100 to replace. 
  • The salt chlorine generator has a control panel that also lasts for 3-7 years, and costs about $500 – $900 to replace. 

The life span of these components depends on how well-made they are to begin with, how well-balanced your pool water is, and on how well they are maintained. 

A lot of people do the math on their existing fresh water pool maintenance costs and time investment, and feel that the investment equals out over time. And many other people feel that it’s worth the additional cost to have a pool with water that looks and feels so nice, with no irritating chloramines. 

Since pool maintenance costs vary so much, depending on the size of your pool, your climate, and your preferences, salt water pool conversion may not be the right choice for everyone, and the cost can be a big drawback. 

Choosing a Salt Chlorine Generator

The salt chlorine generator is the largest investment you make in a salt water pool, so it’s important to choose the right one. Although there’s no need to spend more money than you have to, an inadequate or low-quality generator won’t work well or meet your needs in the long run. Here are some things to keep in mind when shopping for a salt chlorine generator: 

  • The type of pool you have. There are different salt chlorine generators for inground vs. aboveground pools. 
  • The volume of your pool. If you don’t know the water volume of your pool, here is a convenient calculator. Choose a salt cell that is rated for 20-30% more than your pool water volume. In other words, if your pool holds 10,000 gallons, choose a generator rated for 12,000 – 13,000 gallons (or more). Slightly exceeding the salt cell’s rating prevents straining the cell and prolongs its lifespan.
  • The warranty. It’s too bad that a high purchase price doesn’t always mean high quality. Instead, the length of the warranty is a better indicator of the quality of a salt water generator, and helps you better plan for future costs, repairs, or replacements. 
  • The specs. If you can, read the owner’s manual before you buy the generator. Check for details like the pump flow rate, voltage, chlorine output, salt levels, and cleaning and maintenance needs to make sure it’s a good fit for your pool.  
  • The details. While you should always verify with your own testing and inspection, many salt chlorine generators have indicator lights that show when salt levels are incorrect, or the unit needs cleaning. These can be nice features to have, particularly if you are more relaxed about maintaining your pool water. 

How to convert from a fresh water to a salt water pool 

The good news is, you don’t necessarily have to drain your pool in order to convert it to salt water. 

However, if you use antibacterial agents in your pool, then draining it is a good idea. Antibacterial products are incompatible with salt chlorine generators, and make it difficult to keep the pool clean and balanced. You can remove these products by draining the pool, or by “burning” it out with a very high dose of chlorine, which can take several days. 

If/when your pool is free of antibacterial agents, you can begin to convert it to a salt water pool. Here’s how: 

  • Step 1: Test the water. Your pool should be tested and balanced to the specifications of your salt chlorine generator. Remember that balancing a pool takes time, and the pool should be balanced in this order: 
    • Chlorine
    • Alkalinity
    • pH
    • Stabilizer
    • Calcium 
    • Hardness
    • Metals
    • When you adjust your pool, any changes you make tend to adjust all the other values, so doing it in this order allows you to save time. Once your pool is balanced, you are ready to proceed. 
  • Step 2: Inspect your liner. If you have a vinyl pool liner, inspect it carefully. Allowing salt water to corrode your pool galvanized walls will eventually damage or destroy your pool wall, so be cautious. Make sure the vinyl is completely intact, or take this opportunity to make any necessary repairs. 
  • Step 3: Add your pool salt. Follow the instructions for your salt chlorine generator, and salt your pool. It should be spread over the surface of the pool, and given 24 hours to completely dissolve. 
  • Step 4: Install your salt chlorine generator. Once your pool is balanced to the desired levels for your device, you are ready to install it. Installation will take most of a full day, and involve some electrical wiring, so this may be a job to hire out instead of DIY. 

How to Care for a Saltwater Pool

Salt water pools create only as much chlorine as they need, and are naturally more alkaline than acidic. Because the water doesn’t smell, stays clear, and doesn’t irritate the eyes or skin, a salt water pool can become very unbalanced before it is uncomfortable. 

But it’s still important to do regular maintenance of a salt water pool. Here’s how to take care of a salt water pool: 

Once a week: Test the water for Free Chlorine and pH. If necessary, adjust the chlorine output on the chlorine generator. Adjust the pH with muriatic acid or with soda ash or baking soda, just as you would with a fresh water pool. 

Once a month: Test the water for Salt, Alkalinity, Stabilizer, and Calcium. Most salt chlorine generators have a visual indicator when salt levels are low, but manually testing helps you know that the device is working properly. 

Every 3 months: Inspect the salt chlorine generator. Again, many will have a visual indicator that lets you know if maintenance is needed, but it’s good to check. Look for dirt or debris that may have bypassed the filter. Clean off any mineral scale that may have accumulated inside the generator. To clean mineral scale, try using a hose or water to remove it, or follow the manufacturer’s instructions. The cell should be cleaned regularly, but gently, to prolong the life of the cell. 

Seasonally: Over winter, most manufacturers recommend removing the actual salt cell from your salt chlorine generator and storing it inside, and replacing it with a dummy cell. It’s also important to visually inspect your pool lighting, fixtures, and features for any sign of corrosion due to salt water. If you have a vinyl pool liner with galvanized walls, even a tiny leak will cause corrosion. 

Conclusion

If you find that pool maintenance is too time consuming, or if your pool irritates your skin and eyes, damages your hair, fades bathing suits, or smells bad to breathe, then consider switching to a saltwater pool. 

While the initial investment in a salt chlorine generator can be high, many people feel like it’s a good trade-off for reduced maintenance over time, and a nicer experience in the water. 

Categories: Pool Care, Pool Construction