What a conversion actually is
Converting a pool to salt water sounds like a major project. In most cases it is an equipment upgrade. The pool, the pump, the filter and the plumbing all stay. One device is added, salt goes into the water, and the pool starts making its own chlorine.
The water is still sanitized by chlorine afterwards. If that is news, read how salt water pools work first.
What to check before converting
This is the step people skip, and it is where conversions go wrong. A pool built for traditional chlorine was not necessarily specified with salt in mind.
| Check | What to look for |
|---|---|
| Heater | A cupronickel or titanium heat exchanger. Plain copper wears faster in salt water. |
| Lights, rails and ladders | Marine-grade stainless or composite. Rust spots now will get worse. |
| Coping and decking | Soft limestone or sandstone should be sealed, or accepted as a maintenance item. |
| Bonding | Have an electrician confirm the bonding is intact and add the salt system to it. |
| Automatic cover | Ask the manufacturer whether the tracks and mechanism are rated for salt. |
| Warranties | Some equipment and liner warranties exclude salt systems. |
| Current sanitizer | Pools on biguanide products must be fully converted to chlorine first. |
The reasons behind each of these are covered in how salt water pools are built.
The conversion, step by step
- Choose the system. Pick a salt chlorine generator rated comfortably above the pool's volume.
- Balance the water. Bring pH, alkalinity, calcium and stabilizer into range before adding anything.
- Install the control unit. It mounts at the equipment pad and is wired so it only runs with the pump.
- Plumb in the cell. On the return line, after the filter and heater, with unions so it can be removed for cleaning.
- Bond it. The system is connected to the pool's bonding grid. A sacrificial anode is worth adding now.
- Test the existing salt level. Years of chlorine use leave some salt behind. Know the starting point.
- Add salt. Pool-grade salt, in stages, with the pump running and the generator off. Brush until dissolved.
- Wait a day, then switch on. Retest salt, start the generator at a moderate setting, and check chlorine over the following week.
How much salt it takes
Roughly 83 pounds of salt raises 10,000 gallons by 1,000 ppm. The usual target is around 3,200 ppm, though you should follow the range given for your system.
| Pool volume | Salt to reach 3,200 ppm from zero |
|---|---|
| 10,000 gallons | About 267 lb |
| 15,000 gallons | About 400 lb |
| 20,000 gallons | About 534 lb |
| 30,000 gallons | About 800 lb |
Subtract whatever is already in the water.
What changes afterwards
- You stop adding chlorine as a weekly routine.
- You keep testing. Chlorine and pH weekly, salt monthly.
- pH will drift upward and need small, regular corrections.
- The cell is inspected for scale every few months and replaced after several years.
- In cold water the cell stops producing, so chlorine is added by hand early and late in the season.
The routine is laid out in the maintenance guide.
When to convert, and when to wait
- If the equipment and stone are already salt-tolerant
- Convert. It is a simple upgrade.
- If the heater is old copper and due for replacement
- Replace it with a salt-rated one at the same time.
- If the coping is soft stone you love
- Seal it and accept the upkeep, or stay with chlorine.
- If the pool is due for resurfacing or renovation
- Do it together, and specify everything for salt.
- If you are unsure whether salt is worth it
- Read salt water pool vs chlorine pool first.
