Quick Answer
To increase pool pH, add soda ash (sodium carbonate) at 6 oz per 10,000 gallons to raise pH by 0.2 units, or use borax for gentler adjustment. Always test first, add chemicals to deep end with pump running, and retest after 4-6 hours.
Tools & Supplies Needed
Find on Amazon: Taylor K-2006 Pool Test Kit , Soda Ash pH Increaser , 20 Mule Team Borax
First, Let's Diagnose Your pH Problem
Before adding any chemicals, you need to determine exactly how low your pH is and identify what's causing the drop. Low pH (below 7.2) can cause serious problems including equipment corrosion, eye irritation, and reduced chlorine effectiveness.
Test your water using a reliable test kit like the Taylor K-2006 or a quality digital tester. Don't rely on test strips for accurate pH readings. You'll also want to test your total alkalinity (TA), as this directly affects pH stability. If your TA is below 80 ppm, that's likely why your pH keeps dropping.
Choose Your pH Increaser Chemical
You have two main options for raising pool pH, each with distinct advantages:
Soda Ash (Sodium Carbonate) - The Fast Option
Soda ash is the most common and effective pH increaser. It works quickly but can cause temporary cloudiness and will also raise your total alkalinity slightly (about 7 ppm TA increase per 6 oz in 10,000 gallons).
Borax (Sodium Tetraborate) - The Gentle Option
Borax raises pH more gradually with minimal impact on total alkalinity. It's ideal when your TA is already in the proper range (80-120 ppm for regular pools, 60-80 ppm for salt water generators). However, borax is harder to find and more expensive than soda ash.
Step-by-Step pH Raising Process
- Calculate the dosage needed: For soda ash, use 6 oz per 10,000 gallons to raise pH by approximately 0.2 units. For borax, use 20 oz per 10,000 gallons for the same 0.2 pH increase. Never try to raise pH more than 0.4 units in a single treatment.
- Ensure proper circulation: Turn on your pool pump and let it run for at least 30 minutes before adding chemicals. The water should be circulating well throughout the treatment process.
- Pre-dissolve the chemical: Fill a clean plastic bucket with pool water and slowly add your measured chemical while stirring. This prevents undissolved granules from settling on pool surfaces and potentially causing staining.
- Add to the deep end: Pour the dissolved solution slowly into the deep end of your pool near a return jet. This ensures better mixing and distribution throughout the pool.
- Continue circulation: Keep your pump running for at least 4-6 hours after adding the chemical. This allows for complete mixing and chemical distribution.
- Retest and adjust: Wait 6-8 hours before retesting your pH. If it's still below your target range (7.4-7.6), repeat the process with another measured dose.
Addressing the Root Cause
If your pH constantly drops, you need to identify and fix the underlying issue:
- Low Total Alkalinity: If TA is below 80 ppm, raise it first using sodium bicarbonate (baking soda). Add 1.5 lbs per 10,000 gallons to increase TA by 10 ppm.
- Acidic Source Water: Some areas have naturally acidic fill water. You may need to treat new water additions.
- Heavy Bather Loads: Body oils, sweat, and urine are acidic and will lower pH. Ensure adequate sanitization and consider shocking more frequently.
- Trichlor Tablets: These popular chlorine tablets are highly acidic (pH 2.8). Consider switching to liquid chlorine for daily sanitization and using tablets only occasionally.
- Acid Rain: In areas with air pollution, rainwater can be quite acidic and affect your pool's pH.
Safety Precautions and Important Warnings
Never mix chemicals directly: Always add chemicals to water, never water to chemicals. Store different pool chemicals separately and never mix them in storage.
Wear safety equipment including goggles and gloves when handling any pool chemicals. Both soda ash and borax are alkaline and can cause skin and eye irritation.
Avoid swimming for at least 30 minutes after adding soda ash, or until the water clears if cloudiness occurs. With borax, you can typically swim immediately after adding since it dissolves completely and works more gently.
Monitoring and Maintenance
Test your pH at least twice weekly, preferably using the same test method each time for consistency. pH naturally tends to rise in pools due to aeration, outgassing of CO2, and swimmer activity, but certain conditions can cause it to drop consistently.
Keep detailed records of your chemical additions and test results. This helps you identify patterns and adjust your maintenance routine accordingly. If you find yourself constantly fighting low pH despite addressing obvious causes, consider consulting with a local pool professional for a comprehensive water analysis.
Remember that pH affects chlorine efficiency dramatically. At a pH of 6.8, your chlorine is about 10% more effective than at 7.8, but the cost in equipment damage and bather comfort isn't worth this slight sanitizer boost. Maintaining pH in the ideal range of 7.4-7.6 ensures optimal chlorine efficiency while protecting your equipment and swimmers' comfort.
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