Can High Pool Alkalinity Cause a Green Tint in Water?

Alkalinity

• The total alkalinity in your swimming pool measures the amount of alkaline present in the pool water. Typical alkalinity levels should range somewhere between 80 parts per million (ppm) and 120 ppm as indicated by a water test kit. Alkalinity serves as a way of stabilizing the pH readings. When the alkalinity is high, the pH will have a hard time staying within its normal ranges, which can make the water cloudy.

High Alkalinity

• High levels of alkalinity can lead to cloudy pool water that is improperly sanitized which, if neglected can lead to a green pool water. High alkalinity results from adding too many alkalinity-increase chemicals to your pool. High alkalinity levels can also occur during the pool's initial fill up if your local water supply is high in total alkalinity. Whatever the reason, you should lower high alkalinity as soon as you become aware of the problem.

Green Tint

• The green tint in the pool water is actually a bacteria multiplying green algae bloom in your pool. Green algae can form very quickly in warm weather but is more easily combated than other forms of algae. A lack of chlorine or sanitizer in the water is the main culprit for green water. When there is not enough sanitizer present in the water, bacteria grows and affects the other aspects of water chemistry such as alkalinity, pH or calcium hardness. High alkalinity can result in cloudy pool water, which makes the chlorine less effective and can eventually lead to algae if not treated properly.

Remedy

• A treatment of chlorine shock is usually to get rid of green algae from your pool. Start by brushing the pool walls and vacuuming the bottom. Run the filter continuously while trying to eliminate the algae because the shock will need to circulate throughout the pool. Add a dosage of shock appropriate for your size pool and let the filter run for 24 hours. You may need to brush the pool again and repeat to completely eliminate the algae.