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How to Convert a Saltwater Pool to a Chlorine Pool

Saltwater pools offer plenty of benefits, but there’s no doubt that they’re more complicated than traditional chlorine pools.

Switching to a chlorine pool will prevent you from having to maintain the salt cell, generator, and other pieces of the saltwater pool puzzle. However, incorrect conversions can permanently damage the pool’s equipment and chemistry.

To convert a saltwater pool to a chlorine pool, follow these steps:

  • Test the chemistry
  • Partially drain the pool
  • Remove the cell and generator
  • Choose your preferred sanitizer
  • Shock the water
  • Adjust the CYA
  • Maintain the pH and alkalinity

In this post, I’ll dive into the step-by-step process of converting your swimming pool from saltwater to chlorinated water. Make sure you follow the steps in the listed order for the best results.

Test the Salinity, TDS, and Stabilizer

The most important part of switching from a saltwater pool to a chlorinated pool is testing the chemistry. You need to know the salinity, total dissolved solids, and cyanuric acid levels before trying anything else. All swimming pools have salt, TDS, and stabilizer in them, but saltwater pools have higher levels of all three factors.

When you’re maintaining a saltwater pool, the salinity is often above 3,500ppm. However, it needs to be much lower in a chlorinated pool. Let’s jump into the details below.

  • To convert to a chlorine pool, the salinity needs to be below 500ppm (preferably much less). Chlorine pools inevitably have salt in them because liquid chlorine is made with sodium. However, too much of it will alter the pool’s chemistry.
  • The TDS (total dissolved solids) need to be below 2,000ppm, though I typically recommend keeping them far below 500ppm. Saltwater pools often have a lot of TDS because the salt counts as a dissolved solid. However, too much TDS in a chlorine pool prevents other chemicals from dissolving.
  • Saltwater pools need about 90ppm of cyanuric acid, while chlorinated pools need a CYA level between 40ppm to 80ppm. A slight drain is often enough to correct the difference.

Partially Drain the Swimming Pool

Draining the pool can reduce the salinity, TDS, and CYA in the pool, which is why the chemistry needs to be tested beforehand. It’s important to know these measurements to know how much water needs to be removed from the pool. For example, if you have a 3,000ppm TDS, you need to drain about ⅔ of the pool, then refill it.

Draining the pool will always change the water’s chemistry. You’ll have to add a handful of chemicals to the water once these three factors have been adjusted. Here’s a brief list of what you’ll likely have to add:

  • Chlorine
  • Alkalinity and pH adjusters
  • Algaecides

A perfect drain will maintain the calcium hardness and stabilizer in the water.

Pro Tip: Never drain more than ⅓ of the pool at a time. Excessive drainage can damage the swimming pool. Vinyl and fiberglass can cave in, breaking the liner immediately. Gunite and plaster can get too dry and cracked. Drain the pool, fill it to the top, then repeat the process if necessary.

Remove the Salt Cell and Generator

Removing the salt cell and generator isn’t a necessary step, though they’re completely useless and in the way. These parts aren’t necessary to sanitize the pool. Furthermore, they might damage the rest of the equipment if they turn on without enough salt in the water.

Here’s how to remove the cell and generator from the plumbing:

  1. Turn off the power going to the equipment pad.
  2. Cut the PVC around the salt cell and sensor, then replace it with a straight pipe of the same dimensions.
  3. Remove the wires going from the salt generator to the circuit breaker, then unscrew the retaining bracket and screws holding the generator to the wall.

I prefer getting this step out of the way because these parts are frustrating to remove once the pool is fully converted to chlorine. The generator will beep around the clock because the chemistry isn’t suitable for saltwater.

Decide How to Chlorinate the Pool

There are many ways to chlorinate a swimming pool, including tablets, liquid chlorine, and granular chlorine. You can also use in-line and offline chlorine dispensers in the plumbing. They carry chlorine tablets that passively sanitize the water.

Consider these three methods to decide how you want to chlorinate the pool:

  • Liquid chlorine is one of the most common ways to chlorinate water. It’s cheap, convenient, and easy to use. However, it’s not as potent as granular chlorine, and it adds a lot of salt to the water.
  • Granular chlorine is the strongest form of chlorine. It’s a bit pricey, but you get what you pay for. In the Swim’s Granular Chlorine has 68% available chlorine compared to most liquid chlorine’s 8% to 12% chlorine. This 50-pound bucket lasts several swimming seasons, preventing algae and clearing the water.
  • Chlorine tablets are the best way to maintain your pool’s chlorine without much maintenance. These tablets sit in a floater and float around the swimming pool. They need to be changed weekly, but they slowly dispense cyanuric acid in the pool. Natural evaporation usually prevents the CYA from getting too high.

Shock the Water Immediately

Use the previously mentioned granular chlorine to shock the water for the best results. Shocking the pool often requires liquid or granular chlorine. I prefer granular chlorine because it’s much stronger and acts quicker than any other type of chlorine. Keep in mind that you need to use enough shock to open the pool and convert it to chlorine.

Keep these things in mind when shocking a converted swimming pool:

  • Powder shock will cloud the pool for a couple of hours, but this goes away quickly.
  • Always circulate the water for several hours after adding liquid or granular chlorine.
  • Use enough shock to elevate the pool’s chlorine to 4ppm (or 6ppm if there’s an algae bloom).

Adjust and Maintain the Cyanuric Acid

Since saltwater pools need more CYA than chlorine pools, you’ll have to lower the cyanuric acid when switching to chlorine. The good news is that the previous drain in the second step of the post will undoubtedly lower the pool’s cyanuric acid. Test the stabilizer after filling the pool with fresh water to know if you need to add any.

Remember, a chlorine pool’s CYA should be between 40ppm to 80ppm. If your pool is near the lower end, you could add chlorine tablets since they come with CYA.

In the Swim’s Chlorine Tablets are three-inch pucks that sit in a floater. They dispense 90% of available chlorine and stabilizer throughout the week.

Test and Correct the Pool’s pH and Alkalinity

Saltwater pools often combat high-pH issues. The higher pH levels raise the alkalinity, calcium hardness, and other chemicals. Draining and refilling the pool will alter the pH, alkalinity, chlorine, calcium, and almost every other chemical.

If you don’t need to drain the pool, it’s important to lower the pH of the pool. A high-pH pool will stain the walls and cause calcium buildup.

To lower the pool’s pH and chlorine, you’ll need dry acid or muriatic acid (liquid pool acid).

I recommend the EcoCleans pH Down to reduce your pool’s pH and alkalinity. This tub contains 25 pounds of dry acid, which is more than enough for several pool seasons. You can store it for multiple years in a cool, dry place without worrying about expiration.

Once you convert the pool from saltwater to chlorinated water, all of the chemicals need to be maintained at the following levels:

  • Keep the pH between 7.2 to 7.8.
  • Maintain the alkalinity between 80 to 120.
  • Don’t let the calcium hardness get above 400.
  • Drain the water if the TDS is above 2,000ppm (some experts suggest draining the water at 1,500ppm).
  • Keep the cyanuric acid between 40ppm to 80ppm.