Why Isn't My I-PURE Salt Chlorine Generator Raising Chlorine Levels? – Intermatic Support

Applies To

I-PURE Salt Chlorine Generator

Why is my pool’s chlorine level not increasing when the I-PURE salt chlorine generator is running?

The pool pump not operating properly.
Salt levels are too low or too high.
The pool’s exposure to sun, rain, and normal activity can increase chlorine demand.
Cell scaling, fouling, or damage can reduce chlorine output.
Improper water balance, such as high pH, low cyanuric acid (CYA), or high phosphate levels, can also lower system performance.

Follow these steps in order Test free chlorine before and after each step using fresh reagents.

Verify System Operation and Chlorine Production
Ensure the pool pump is running and the I-PURE control panel shows normal status (no error codes). Inspect the clear cell housing while operating. You should see steady small bubbles (hydrogen gas) and a milky or hazy flow, which are signs of electrolysis. If no bubbles are visible, clean the cell immediately and check for flow restrictions such as a dirty filter or closed or mispositioned valves. Refer to the manual for diagnostic codes.
Confirm Salt Level
Test salt level with a calibrated meter or quality strips. Target: 3,000-3,500 ppm. If salt level is too low, add pool-grade salt per the manual. As a rough guide, about 25 lb raises approximately 1,000 ppm in a 10,000-gallon pool. Circulate for 24 hours, then retest. If salt level is too high, partially drain and refill with fresh water, then retest.
Assess and Reduce Chlorine Demand
After heavy use, storms, or debris, shock with liquid chlorine to reach 10-20 ppm free chlorine, or use a non-chlorine oxidizer as appropriate. Brush walls and floor, vacuum to waste if needed, and skim surface organics. Run the pump 24-48 hours after shocking to filter out contaminants, then retest free chlorine.

Balance Water Chemistry (Critical for Chlorine Effectiveness)

Use a reliable test kit (for example, Taylor K-2006). Adjust in this order:

Parameter	Target Range	Notes
pH	Concrete: 7.4-7.6; Fiberglass/Vinyl: 7.2-7.4	High pH (>7.8) reduces chlorine activity; lower with muriatic acid.
Cyanuric Acid (CYA)	30-60 ppm	Protects chlorine from UV. Too low = rapid loss; too high (>80 ppm) = weak sanitizing.
Total Alkalinity (TA)	80-120 ppm	Buffers pH. Adjust after pH.
Phosphates	<100 ppb	Fuel algae; use a phosphate remover if elevated.

Salt systems tend to raise pH over time. Check pH weekly and correct as needed.

Clean and Inspect the Cell
Turn off the pump and system. Follow the “Chlorinator Maintenance” section in your I-PURE manual. If scaled, soak the cell in a 1:4 muriatic acid solution or approved cleaner for 15-30 minutes, then rinse thoroughly. Inspect plates for damage or cracks and replace if needed. Reinstall and verify bubble production within 1 hour of restart.
Optimize Runtime and Output
Run the pump 8-12 hours per day as a baseline, up to 24 hours during peak season or when free chlorine is persistently low. Increase I-PURE output in small steps (around 10 percent increments) and retest free chlorine. Confirm the system is correctly sized.
Validate Test Results
Ensure reagents are not expired. If readings fluctuate, take a sample to a professional pool store for cross-verification. Track free chlorine, pH, salt, and notes on usage and weather.
Rule Out Hidden Consumers
Early algae or biofilm can consume chlorine before it is visible. Add a maintenance dose of polyquat-60 algaecide, brush and vacuum thoroughly, and retest free chlorine after 24 hours. If free chlorine drops overnight by more than 1 ppm with the pump off, perform an Overnight Chlorine Loss Test.

Establish a base chlorine level before relying solely on the I-PURE system.
Shock the pool with liquid chlorine or a non-chlorine oxidizer if chlorine remains low after adjustments.
Brush and vacuum the pool and use algaecide as needed to eliminate organic contaminants.
Test and balance cyanuric acid, pH, total alkalinity, and phosphate levels regularly.
Salt systems naturally raise pH over time; check and correct weekly.
Confirm salt levels remain between 3,000-3,500 ppm.
Adjust runtime or chlorinator output as needed.
Always follow manufacturer instructions when cleaning or maintaining the cell.