There are two main products for lowering the pH. These are sodium bisulfate (also known as dry acid) and muriatic acid.
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.
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.
Typically, you use acids to lower the pH level in your water. Hydrochloric acid (also known as muriatic acid) lowers pH levels in water. You can purchase muriatic acid at most hardware stores; it is typically used to clean bricks.
Depending on what PH you wish to achieve, adding a little baking soda will simply not affect the PH level of your pool, thereby causing it to remain almost the same way (acidic). However, adding too much baking soda might also raise the PH level of your pool to an undesired stage (alkaline).
To bring down pH, use a made-for-pools chemical additive called pH reducer (or pH minus). The main active ingredients in pH reducers are either muriatic acid or sodium bisulfate (also called dry acid). Reducers are readily available at pool supply stores, home improvement centers and online.
The most common reason for a consistently high pH level in pools is the use of liquid chlorine or a saltwater system as the primary sanitizer. Sodium hydroxide is produced, which has a pH of around 13. New pool plaster or pebble finishes will also raise pH in pools for about a year after installation.
For Ph. down use Aluminum Sulfate. You can get it from garden centers, it's used for acid loving plants and making Hydrangeas Blue. only use a few grains per liter to start as it's quite strong.
How do I lower the pH in my water naturally? A simple way to lower the pH in your water naturally is to use lemon juice. Simply drop 2-3 drops of lemon juice to an 8 fl oz (240 mL) glass of water. The acidity of a lemon naturally lowers the pH level of the glass of water.
White Vinegar
It's calcium buildup, and while it doesn't damage your pool or the water, it doesn't look great, either. Just like you run vinegar through your coffee pot to get rid of calcium buildup, white vinegar can wipe away this eyesore in your pool.
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.
If you wish to lower the pH without also reducing the Total Alkalinity, simply pour the dose of muriatic acid about the pool. “ This would all be wonderful if it was only accurate. Still, just like the mythological “Chlorine Lock,” folkloric tales within the swimming pool industry do persist.
To make the pH level of 100 ml of water lower down to around 5.5, you will only need a drop of lemon or lime juice. Experts also estimate that to adjust the pH of a gallon of water, two drops of pure lemon juice can lower pH levels by 0.5. You can add more if needed.
The basic ingredients of pH DownTM are phosphoric acid, citric acid, and mono ammonium phosphate. DANGER! CORROSIVE.
Using vinegar temporarily reduce the pH of water which is not stable for longer time. Using phosphoric acid though better than acetic acid and reduces pH for longer time but phosphoric acid reacts with Calcium ions and form insoluble precipitation.
If using alkaline water can result in pH climb over time from precipitates, you could imagine that using citric acid (a soluble crystal) to water could also result in a buildup of citric acid in the media, dropping the pH a bit lower each time.
A pH level of 7 means that water is neutral; above 7 means the water is alkaline, while below 7 indicates acidity. Aim for a pH level of between 7 and 7.6. If the water pH is higher than 8, anyone who swims in the pool is at risk of skin rashes, while a pH of lower than 7 can sting swimmers' eyes.
High chlorine levels decrease the pH of your pool's water, making it more acidic. The more acidic the water, the higher the likelihood of corrosion. This corrosion can affect metal piping, equipment, and the surface of your pool (tiles, liners, concrete, etc.).
Vinegar is acidic. Vinegar's pH level varies based upon the type of vinegar it is. White distilled vinegar, the kind best suited for household cleaning, typically has a pH of around 2.5. Vinegar, which means “sour wine” in French, can be made from anything containing sugar, such as fruit.
Baking soda, also known as sodium bicarbonate is naturally alkaline, with a pH of 8. When you add baking soda to your pool water, you will raise both the pH and the alkalinity, improving stability and clarity.
Along with balancing the pH levels of your pool water, muriatic acid is strong enough to kill mold, remove rust stains, get rid of calcium deposits, and clean the surfaces of your pool.
To raise the pH levels in your pool, try adding sodium carbonate (soda ash) or sodium bicarbonate (baking soda) until your pool's pH levels are between 7.2 and 7.8.
The use of baking soda in pools can spot treat algae
No one ever wants to see algae build up in their swimming pool. It can turn any backyard pool murky green or cause unsightly black spots on the walls and floor of any swimming pool.
Both baking soda and soda ash are great options for use in your pool, however, their uses may vary depending on your chemical levels. Use soda ash for when you want to raise both pH and alkalinity and use baking soda when you want to raise alkalinity without raising pH too much.
The short answer is (you may have guessed it): no. It's not the best idea to clean your pool with vodka. Michael Dean, Co-Founder at Pool Research, a site that provides expert advice on all things related to pools, spends a lot of time advising people on how to clean their pools.