Maintaining proper pool water chemistry is crucial for the health of both your pool and swimmers. Regular water testing helps ensure that the pool water remains balanced, safe, and clean. Here’s an in-depth look at pool water testing, chemistry, and the necessary steps to maintain the right balance:
Pool Water Chemistry
Maintaining a balanced pool is essential for swimmer safety and the longevity of your pool equipment. Three key factors you need to monitor regularly are pH levels, alkalinity, and calcium hardness. If these levels are not properly balanced, it can lead to skin irritation, water clarity issues, or even damage to your pool’s surfaces and equipment.
PH Levels
The pH level of your pool water determines how acidic or alkaline it is. The ideal pH for pool water is between 7.4 and 7.6. If the pH drops below 7.4, the water becomes too acidic, which can lead to red, irritated eyes and skin. On the other hand, a pH level above 7.6 makes the water too alkaline, which can cause scaling and the formation of calcium deposits on the pool surfaces. To correct these issues, you can add acid to lower the pH or baking soda to raise it.
Alkalinity
Alkalinity refers to the concentration of hydroxides and carbonates in the water and helps stabilize pH levels. The optimal range is 80 to 120 ppm. If alkalinity falls below 80 ppm, it can cause pH levels to fluctuate. Frequent backwashing may be a cause. To correct this, you can add alkalinity increaser. Levels above 120 ppm are rare but may require a pool specialist’s help to adjust.
Calcium Hardness
Calcium hardness measures the amount of calcium in the water, and maintaining the right levels prevents issues like water stains or corrosion. For tiled or concrete pools, the ideal range is 200-300 ppm, while for vinyl or fiberglass pools, it’s 100-250 ppm. Low calcium levels can cause damage to pool surfaces, while high levels lead to cloudy water and scaling. To correct low calcium, add calcium chloride. For high calcium, partial water changes or a calcium reducer can help.
How to test your pool water
Testing your pool water is surprisingly much simpler than you think! There are 3 recommended options to test your pool water and 2 of them don’t involve leaving the house. Pool test strips, liquid test kits, or taking a water sample to your local pool shop.
Test strips
These are quick, affordable, and simple. Dip the strip into the water, wait for a few seconds, then match the colour on the strip to the chart on the bottle for results.
Liquid test kit
These are more precise. After filling a vial with water, add specific drops of reagents, wait for the colour change, and compare it to a chart for accurate readings.
Local pool shop test
Pool shops often offer free water testing. Simply collect a sample of pool water in a clean bottle, take it to the shop, and let professionals run a detailed test.
It is important to get a accurate sample of water prior to taking it to the pool shop, steps below will guide you to correctly collecting a water sample.
- See your local pool shop for a pool water sample bottle
- Turn pool filter on and let run for 5-10 minutes
- Since the container with pool water 2-3 times
- Hold the bottle upside down as you put it into the pool (bottle opening facing down)
- Hold the bottle up to the pool jets and turn 90DEG so the jet water will ender the bottle
- Bring the bottle back to the surface once completely full
- Keep bottle cool, sample must be completed same day as sample
The test at your local pool shop will take no longer than 10 minutes, they will do a complete test of your water and recommend chemicals required to your pool. This is recommended to be done on a monthly basis.
Pool water test results
It is always recommended to have your pool water professionally tested prior to adding any chemicals to your pool. Your local pool shop specialist will recommend the correct product for your pool needs.
PH Levels
PH levels to be between 7.4 – 7.6
Level below 7.4 – your pool is to acidic, this will cause red irritated eyes and skin. Add baking soda or Alkaline.
Level above 7.6- the pool has to much alkaline, this will promote scaling and calcium formation in the pool and pool system. Recommend to add Acid to lower.
Alkalinity
Alkalinity levels to be between 80 to 120 ppm
Level below 80 – your pool may be getting back washed to frequently. Add some Alkaline to the water.
Level above 120- This is very rare, unless to much alkaline was manually added. Speak to a pool specialist for options to lower.
Calcium Hardness
Calcium hardness to be between 200-300PPM for tiled/concrete pools and 100-250PPM for vinyl/fibreglass pools.
Levels below 200 – Caused by frequent wattle top up. Add calcium to pool to prevent any damage to concrete, tiles and pool grout.
Levels above 300PPM – to much calcium manual added to pool water. Adding fresh water to your pool will lower the calcium levels in the pool. If you have extremely high levels of calcium, levels above 400PPM it is recommended to add a calcium Down chemical which is specifically formulated to lower the calcium in water.
Chlorine
Chlorine levels to be between 2-4 ppm
Levels below 2PPM- There are multiple reasons it could be low, low salt, salt cell requires cleaning, chlorinator settings to low. Check pool setting with pool professions.
Levels above 4PPM- Your pool may have been over dosed with manual chlorine or the chlorinator is turned up to high. Check the chlorinator setting with pool professional and add chlorine remover to the pool water.
Cyanuric Acid
Cyanuric Acid levels to be between 30 – 50PPM
Levels below 30PPM- The UV in the sunlight will dissolve the chlorine in your pool. Add Cyanuric Acid to the water.
Levels above 50PPM- To much stabiliser has been added to the water. Either wait 2-3 months and it will dissolve on its own. Discuss options with pool professionals.
Salt
Salt levels to be between 2700-3400 ppm
Levels below 2700PPM- Salt has dissolves and flushed from water. Add salt to water
Levels above 3400PPM- To much salt added. Drop water level and add fresh water to pool.