Quick Answer
Salt water pools can cause diarrhea if the salt cell isn't producing adequate chlorine or if the water is contaminated with harmful bacteria. The solution is maintaining proper free chlorine levels of 1-3 ppm and balanced pH.
Tools & Supplies Needed
Find on Amazon: Taylor K-2006C Pool Test Kit , Liquid Chlorine Sanitizer , Salt Cell Cleaning Stand
Quick Answer
Yes, salt water pools can cause diarrhea if the sanitizer levels are inadequate or the water becomes contaminated with harmful bacteria like E. coli, Cryptosporidium, or Giardia. The immediate solution is to test your free chlorine levels and ensure they're maintained at 1-3 ppm with proper pH balance of 7.4-7.6.
Why Salt Water Pools Can Cause Digestive Issues
Many pool owners mistakenly believe salt water pools are "chemical-free," but they still rely on chlorine for sanitization. The salt chlorine generator converts salt into hypochlorous acid (the same sanitizer as liquid chlorine). When this system fails or operates inefficiently, dangerous pathogens can multiply rapidly.
Common Contamination Sources
- Fecal contamination: Even microscopic amounts introduce harmful bacteria
- Animal waste: Birds, raccoons, and pets can contaminate the water
- Storm water runoff: Rain can wash contaminants into your pool
- Inadequate filtration: Poor circulation allows bacteria to establish colonies
- Bather load: Too many swimmers overwhelm the sanitizer system
Testing and Diagnosing the Problem
Start by testing your water chemistry immediately using a reliable test kit like the Taylor K-2006C. Focus on these critical parameters:
Free Chlorine Levels
Your free chlorine should read 1-3 ppm consistently. Salt water pools often struggle with chlorine production, especially when:
- Salt levels are below 3,200 ppm or above 3,800 ppm
- The salt cell is scaled or needs cleaning
- Water temperature is below 60°F (reduced cell efficiency)
- Cyanuric acid levels are too high, binding available chlorine
pH and Total Alkalinity Balance
Maintain pH at 7.4-7.6 and total alkalinity at 60-80 ppm for salt water pools. High pH (above 7.8) dramatically reduces chlorine effectiveness, even when readings appear adequate.
Immediate Solutions to Prevent Illness
Emergency Sanitization Protocol
If you suspect contamination or have inadequate chlorine levels:
- Shock the pool immediately: Add liquid chlorine to raise free chlorine to 10 ppm
- Run filtration continuously: Keep your pump running 24 hours until levels stabilize
- Test every 2-4 hours: Monitor free chlorine and add more liquid chlorine as needed
- Maintain shock level: Keep FC at 10 ppm for at least 8 hours with clear water
- Clean the salt cell: Remove calcium buildup that reduces efficiency
Adjusting Salt Chlorine Generator Output
Increase your generator's output percentage gradually while monitoring chlorine production. Most units should operate at 50-80% capacity during swimming season. If you're running at 100% and still can't maintain 1-3 ppm FC, your cell may need replacement or professional inspection.
Long-Term Prevention Strategies
Regular Maintenance Schedule
Weekly tasks:
- Test and balance all chemistry parameters
- Clean skimmer and pump baskets
- Brush pool walls and floor
- Check salt cell for scale buildup
Monthly tasks:
- Deep clean salt cell with muriatic acid solution (4:1 water to acid ratio)
- Inspect and clean pool filter
- Verify salt levels with professional-grade testing
Cyanuric Acid Management
Salt water pools should maintain CYA levels at 70-80 ppm for optimal chlorine protection. However, excessive CYA (above 100 ppm) creates "chlorine lock," where sanitizer becomes ineffective. If CYA is too high, partially drain and refill your pool.
When to Seek Professional Help
Contact a pool professional immediately if:
- Multiple swimmers develop gastrointestinal symptoms
- You cannot maintain adequate chlorine levels despite troubleshooting
- Water appears cloudy or has unusual odors
- Salt cell requires frequent cleaning (monthly or more)
Health Precautions
While addressing water chemistry issues, follow these safety guidelines:
- Avoid swimming until free chlorine reaches and maintains 1-3 ppm for 24 hours
- Shower before and after swimming to reduce contamination risk
- Don't swim if you're experiencing digestive issues to prevent spreading illness
- Supervise children carefully and discourage water ingestion
Remember that properly maintained salt water pools are generally safer than traditional chlorine pools when chemistry is balanced correctly. The key is consistent monitoring and prompt action when problems arise. Your health depends on maintaining that delicate balance between salt cell efficiency, proper circulation, and adequate sanitizer levels.
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