Knowing how to lower pH in a pool keeps it comfortable for swimming. It protects your pool filters, pumps and liners from damage. Water with a high pH level reduces chlorine's effectiveness. This can lead to other problems like cloudy water and algae buildup.
If you have a light green pool, you need to shock your pool in order to kill algae. Algae feeds off high pH levels and chlorine isn't as effective when your pH is high. You will need to lower your pH using hydrochloric acid.
According to Healthfully, algae thrives in water with high pH levels between seven and nine. For most algae growth, an optimum pH is between 8.2 and 8.7. A pH level that is neutral or lower can help decrease the growth of algae.
Algae is certainly the cause of the green, but an imbalance of pH and/or alkalinity is why you have algae in the first place (while there is adequate chlorine). Very high or low pH significantly decreases the effectiveness of chlorine.
Water with a pH that's too high also can cause skin rashes, cloudy water and scaling on pool equipment. Over time, scaling inside pipes can build up, restricting water flow and putting a strain on your pool circulation system that can lead to costly repairs.
When you shock a pool, you test and adjust the pH level for a reason. With that said, if you shock a pool outside of the 7.2 to 7.4 pH range, not only will you waste a significant amount of the chlorine used, you will also end up with cloudy water.
You can lower the pH in your pool naturally by directing the downspouts from your house into the pool. If a pool becomes too full due to backwash it dumps water. Since rain is about 5.6 pH it is going to bring down the pH of the water naturally. The problem that you will have with rainwater is its low alkalinity.
Pool water turns green because of algae in the water. Algae can grow rapidly, particularly when it's warm like Summer, which is why it can surprise you overnight. This generally comes down to an imbalance or lack of chlorine in the water.
When the levels are properly balanced, chlorine will keep the algae at bay, but the water will slowly begin to turn green as the algae take over if there's not enough. But be careful—adding too much chlorine in pool water can cause those metals to oxidize and turn the pool a different shade of green.
During the day, algae absorb carbon dioxide from the water for cell growth, raising pH. At night, photosynthesis stops and algae continue to respire, releasing carbon dioxide and lowering pH. This cycle creates diel fluctuations in pH.
Algal abundance is affected by pH. In one study when the pH was lowered from 6.6 to 5.0, algal abundance increased (Leavitt 1999). Because an increase in algal abundance was observed when lowering the pH, it can be expected that algal abundance should decrease when the pH is raised.
For example, marine algae strains prefer pH usually around 8.2, while freshwater strains prefer pH around 7.0. Meanwhile, spirulina (Arthrospira) prefers a pH of around 10. Second, algae require carbon dioxide, for growth and pH can affect how much is available.
Here are common causes of an alkaline pool: Algae can raise the pH. Adding strong liquid chlorine, calcium or lithium hypochlorite chlorine may raise it. Suddenly heating the water, whether from a pool heater or a string of sunny days, could up the pH.
Algaecides do not directly affect the pH balance in your pool, but too much algae will raise the pH level. ... Algaecide also works together with chlorine, helping the chlorine to be more effective against algae and bacteria.
Algae raises the pH of water too
Algae consume carbon dioxide, which removes it from solution. In effect, this consumption of CO2 raises the pH, and enough algae can raise the pH of your swimming pool well above 8.2.
A nylon or rubber brush is the correct choice for scrubbing the sides of a soft-sided above-ground pool. A large pool brush makes quick work of the job, but you may need a smaller brush to clean corners. Once the particles have been removed from the sides of the pool, turn your filter back on and agitate the water.
Grab a brush and some baking soda. Bicarbonate, the active ingredient in baking soda, is an effective spot treatment to help kill the algae and loosen it from the wall. Make sure you really get every last particle free; black algae has particularly long and stubborn roots which makes it a persistent strand.
Pools can immediately turn green after shocking when they have metals like copper in the water. These metals oxidise when exposed to high levels of chlorine which makes the pool water turn green. Adding a metal control product such as Zodiac Metal Remover will help to restore the pool water.
If the pool is free of algae, the green tint indicates that something is slightly out of balance or there is a presence of a high level of phosphates that can also lead to redundant algae problems.
Ordinary household vinegar could in theory be used to lower the pH of your pool. The pH of vinegar is about 2.5, which is quite acidic when compared to your pool water. Household vinegar is very weak though (when compared to a strong acid like muriatic acid), so you would need quite a bit to lower pH.
Rainfall dilutes pool chemistry levels and lowers the readings for pH, alkalinity, hardness, stabilizer, and chlorine.
In most tap water, well water is alkaline. Test the pH of your water with a pH tester to determine the hardness. Then, add vinegar to water (Not the other way round). Ideally, you can add 2 to 9 tbsp of vinegar to one gallon of water.