How Salt Pools Actually Work
A salt chlorine generator (SCG) converts dissolved salt (NaCl) into chlorine through electrolysis. The salt cell splits sodium chloride into sodium hypochlorite (liquid chlorine) and hydrochloric acid. The chlorine sanitizes the water, then recombines with sodium to form salt again — a continuous cycle.
Key point: Salt pools ARE chlorine pools. They just make their own chlorine instead of you adding it.
Ideal Salt Pool Chemistry Ranges
| Parameter | Ideal Range | Notes |
|---|---|---|
| Salt | 2,700–3,400 ppm | Check manufacturer specs |
| Free Chlorine | 3–5 ppm | Same as traditional pools |
| pH | 7.4–7.6 | Salt pools trend high — check weekly |
| Total Alkalinity | 80–100 ppm | Lower end helps control pH drift |
| Calcium Hardness | 200–400 ppm | Higher protects plaster from soft water |
| CYA (Stabilizer) | 30–50 ppm | Salt cells add NO CYA |
| LSI | -0.3 to +0.3 | Critical for salt pools |
The #1 Salt Pool Problem: pH Drift
The electrolysis process produces sodium hydroxide (a base) as a byproduct, which continuously pushes pH upward. This is the most common issue pool pros face with salt pools.
Solutions:
- Lower starting alkalinity to 70–80 ppm (less buffering capacity = less pH bounce)
- Add muriatic acid weekly as maintenance, not just when pH is already high
- Use a proportional acid feeder for larger commercial pools
CYA Management in Salt Pools
This is critical and often misunderstood:
- Salt cells produce **unstabilized chlorine** — no CYA is added
- Without CYA, sunlight destroys chlorine in 1–2 hours
- You MUST add CYA separately to protect the chlorine output
- Target 30–50 ppm CYA for salt pools
- If CYA gets too high (above 80 ppm), the salt cell can't produce enough effective chlorine
Pro tip: The FC/CYA ratio matters more than the raw FC number. Maintain FC at 7.5% of your CYA level.
Salt Cell Maintenance
Salt cells scale up with calcium deposits, especially in hard water areas. Inspect every 3 months:
- Remove the cell and inspect the plates
- If you see white calcium buildup, clean with a 4:1 water-to-muriatic-acid solution
- Soak for 5–10 minutes (don't use stronger solutions — it damages the coating)
- Rinse thoroughly with a garden hose
- Reinstall and check operation
Cell lifespan: Most cells last 3–5 years (10,000–15,000 hours) with proper maintenance. The lower your LSI, the less scaling and the longer cells last.
LSI Is Critical for Salt Pools
Salt pools are more prone to scaling because:
- The electrolysis process raises pH locally near the cell
- High pH + high calcium = positive LSI = scale formation
Keep LSI below +0.3 to protect the salt cell. Use our LSI calculator at every service visit.
Common Salt Pool Problems
Low Salt Reading
- Check with an independent salt test (not just the cell's reading)
- Rain dilution is the most common cause
- Add pool-grade salt (NOT rock salt or table salt) to raise level
Cell Not Producing Enough Chlorine
- Clean the cell (calcium buildup reduces output)
- Check CYA level (too high means chlorine is less effective)
- Check salt level (below 2,500 ppm and most cells reduce output)
- Cell may be nearing end of life (plates wear out)
Metallic Taste or Staining
- Check copper and iron levels
- Salt systems can accelerate galvanic corrosion between dissimilar metals
- Use a sacrificial zinc anode to protect metal components
Salt Pool vs. Traditional Pool: The Real Differences
| Factor | Salt Pool | Traditional Pool |
|---|---|---|
| Chlorine source | Salt cell generates it | You add it manually |
| CYA management | Must add separately | Often included in trichlor tabs |
| pH trend | Drifts up constantly | More stable (depends on chlorine type) |
| Equipment cost | Higher (cell replacement) | Lower |
| Water feel | Softer | Depends on TDS |
| Service complexity | Higher | Lower |
Track Salt Pool Chemistry with PoolOps
PoolOps records all chemistry readings including salt levels, making it easy to spot trends before they become problems. The built-in LSI calculator accounts for all factors automatically.