How Salt Chlorine Generators Work
When you convert to saltwater, you dissolve high-purity non-iodized pool salt (sodium chloride) into the water until salinity reaches 3,000 to 3,500 ppm (roughly 1/10th the salinity of the ocean). As salted water flows through the electrolytic cell, a low-voltage direct current passes between parallel titanium plates coated with ruthenium oxide:
Electrolysis Reaction: 2NaCl + 2H2O + Electricity -> Cl2 + 2NaOH + H2
Dissolved chlorine gas immediately converts into hypochlorous acid, the active sanitizing form of free chlorine.
Sizing Your Salt Chlorine Generator
The number one mistake homeowners make is buying a salt cell sized for their exact pool volume (such as buying a 20,000-gallon cell for a 20,000-gallon pool). During hot summer months, that cell must run at 100 percent output 24 hours a day to keep up with UV chlorine demand, wearing out its titanium coating in 2 to 3 years.
Sizing Rule: Recommended Cell Capacity = Pool Gallons x 1.5 to 2.0
For a 20,000-gallon pool, purchase a 35,000 to 40,000-gallon rated salt cell so you can run it at 50% output, doubling cell lifespan.
Step-by-Step Conversion Protocol
- Balance water chemistry completely: Adjust pH to 7.4 to 7.6, total alkalinity to 80 to 100 ppm, and cyanuric acid to 60 to 80 ppm before turning on the salt system.
- Plumb the cell in the return line: Mount the electrolytic cell horizontally as the very last piece of equipment on the return plumbing line (after the pump, filter, and heater). This ensures concentrated chlorine does not corrode heater copper cores.
- Wire the control panel to the timer: Connect the power center to a 120V or 240V supply that only energizes when the pool circulation pump is running.
- Broadcast pool-grade salt: Turn off the salt system. Broadcast bags of 99.8% pure evaporated pool salt around the perimeter. Brush the pool floor until all salt dissolves completely (24 hours).
- Power on the generator: Once salt is fully dissolved, turn on the power center and set output to maintain 3 to 5 ppm free chlorine.
Corrosion Protection: The Sacrificial Zinc Anode
Saltwater increases the electrical conductivity of water, speeding up galvanic corrosion between dissimilar submerged metals (such as stainless steel screws, light rings, ladder hardware, and heater elements). Installing an inline sacrificial zinc anode on your plumbing pad bonds to your pool equipment and erodes sacrificially, sparing your expensive metal hardware.
convert pool to saltwater FAQs
How much does it cost to convert a pool to saltwater?
A complete salt chlorine generator system costs between $900 and $2,200 for equipment, plus $400 to $800 for professional plumbing and electrical installation, and $150 to $250 for initial salt bags.
Does salt water taste salty like the ocean?
No. The ocean has a salinity of approximately 35,000 ppm. A saltwater pool operates at 3,200 ppm, which is below the human taste threshold (around 3,500 to 4,000 ppm). Most people notice only a pleasant soft feeling.
Can I add salt to a freshly plastered pool immediately?
No. Newly plastered gunite and marcite pools release calcium hydroxide during hydration. You must wait a minimum of 30 days of daily brushing and water balancing before adding salt; otherwise, salt stains and cures into the fresh plaster.
Why does pH rise so fast in saltwater pools?
The electrolysis reaction produces sodium hydroxide (NaOH) and off-gasses hydrogen micro-bubbles, which aerate the water and drive pH upward. Saltwater pool owners must add muriatic acid regularly to maintain pH between 7.4 and 7.8.
More pool guides
- How to Clean a Salt Cell: Acid Ratio and Calcium Scale Removal
Safely dissolve calcium scale from titanium plates without damaging ruthenium coatings.
- Liquid Chlorine vs Tablets: Which Sanitizer Is Best for Your Pool?
Compare costs, cyanuric acid accumulation, and chemical dosing between liquid chlorine and trichlor pucks.
- Muriatic Acid Pool Safety: Proper Handling, Dilution, and Dosing
Essential safety rules for handling, pouring, and storing muriatic acid around your swimming pool.