Pool pH Too High or Too Low—Causes, Symptoms, and Solutions
Pool pH too high or too low — Causes, symptoms and solutions
pH balance is one of the most important parameters for your pool. An improperly adjusted pH means uncomfortable water, equipment that deteriorates prematurely, and chemicals that lose their effectiveness. Yet, it's also one of the most frequent problems our Piscines Geyser experts encounter with pool owners in the Laurentians and the North Shore.
Here's everything you need to know to understand, detect, and quickly correct a pH problem.
What is pH and why is it so important?
pH measures the level of acidity or alkalinity of your water on a scale from 0 to 14. For a pool, the ideal range is between 7.2 and 7.6.
Why this specific range? Because it's precisely the level that allows:
- Chlorine to work effectively — an improperly adjusted pH can reduce chlorine effectiveness by up to 90%
- The water to be comfortable for swimmers' eyes and skin
- Your equipment to last longer — pump, filter, walls, liner
- Other chemicals to do their job correctly
pH too high — Above 7.6
Symptoms
- Cloudy or milky water despite sufficient chlorine
- Swimmers' eye and skin irritation
- Formation of calcium deposits on walls and equipment
- Ineffective chlorine — you add it but the water remains problematic
- Filter clogs faster
Frequent Causes
- Excessive addition of alkaline products like baking soda
- Abundant rainwater in certain regions of the Laurentians
- Naturally alkaline fill water — common with well water
- Algaecides or shock products with high pH
- Prolonged hot and sunny weather which naturally raises pH
Solutions
To lower pH, use muriatic acid or a pH reducer (pH minus):
- Test your water with strips or a test kit
- Calculate the dose according to your pool's volume
- Add the product directly to the water in front of a return jet, with the pump running
- Wait 4 to 6 hours before retesting
- Repeat if necessary until the 7.2 – 7.6 range is reached
⚠️ Do not swim for at least 4 hours after adding muriatic acid.
pH too low — Below 7.2
Symptoms
- Water that stings eyes and irritates skin
- Very strong chlorine smell — paradoxically, this often indicates a pH that is too low
- Corrosion of metal equipment — ladders, pump, water heater
- Discoloration or accelerated deterioration of your pool liner
- Walls that become rough to the touch
Frequent Causes
- Excessive use of granular or liquid chlorine which acidifies the water
- Acidic rainwater — common in spring in the Laurentians region
- High pool usage — perspiration and urine acidify the water
- Negligence when opening the pool at the beginning of the season
Solutions
To raise pH, use sodium carbonate (pH plus) or baking soda for a gentler correction:
- Test your water with strips or a test kit
- Calculate the dose according to your pool's volume
- Dilute the product in a bucket of water before adding it
- Pour slowly in front of a return jet, with the pump running
- Wait 4 to 6 hours before retesting
The correct order to balance your water
Many owners make the mistake of starting with chlorine. Here's the correct order 👇
- Total Alkalinity (TA) — between 80 and 120 ppm
- pH — between 7.2 and 7.6
- Calcium Hardness — between 200 and 300 ppm
- Chlorine — between 1 and 3 ppm
- Stabilizer (cyanuric acid) — between 30 and 50 ppm
If you correct the pH without first stabilizing the total alkalinity, your pH will continue to fluctuate. This is the most common pitfall!
How often should you test your water?
- In peak season: at least twice a week
- After heavy rain: systematically
- After heavy use: evening, party, high heat
- At the beginning and end of the season: a complete in-store analysis
At Piscines Geyser in Blainville, we offer a free water analysis in-store. Simply bring a water sample and our experts will provide a complete assessment with precise recommendations for your situation.
Products recommended by Piscines Geyser
To effectively correct your pH, we recommend:
- pH Plus — to raise a pH that is too low
- pH Minus / Muriatic acid — to lower a pH that is too high
- Alkalinity Plus — to stabilize alkalinity before adjusting pH
- HTH Test Strips — for quick and accurate home testing
All these products are available in-store in Blainville and on our online shop with fast delivery across Quebec.
Unsure? Our experts are here to help
A pH that constantly fluctuates despite your corrections may indicate a deeper problem — unstable alkalinity, particular well water, or an unsuitable treatment system. In such cases, please do not hesitate to contact us.
📞 450-818-8200 | 1-888-551-5021 (toll-free) 📍 380 Boul. de la Seigneurie O., Blainville, QC 🌐 geyserpiscines.com | 7 days a week
