Through the years I have run across different scenarios of pH and alkalinity some of which are kind of hard to understand or make no sense but as a pool owner-operator, you need to balance the chemistry starting with alkalinity regardless of pH before they have a negative effect on the pool water. How do you fix High pH with Low Alkalinity?
Put pool filter on recirculate
Run pump
Add soda Ash or sodium bicarbonate to raise alkalinity
Evenly distribute powder on the pool’s surface by walking around the pool
Waiting at least 6-8 hours for retesting TA
Once the alkalinity reading is 80-120 ppm
Lower pH to 7.2-7.6 with a pH-down product
The most important reason for balancing the chemistry of your pool or spa is to allow the chlorine to do its job as efficiently as possible because if the pool’s water is not balanced then this renders chlorine ineffective which will allow bacteria to grow and take over. This is why pH and Alkalinity are so crucial to the water chemistry of pool water.
Effects of High pH on Pool Water-Spa Water
If the pH gets higher than 7.8, the water is becoming too alkaline. When water is too alkaline, it reduces the effectiveness of chlorine disinfection the pool chemical that kills pathogens. Pool water with a pH level that’s too high also can cause skin rashes on swimmers, cloudy water, and scaling on pool equipment in a pool and spa.
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 for pool, spa, and hot tubs. Steps should be taken to lower the pH.
A pH reducer added to the pool water will lower the high ph of the water. Chemicals like muriatic acid will lower the pH level of your pool water. Doses of muriatic acid should be taken in steps to the pool water and tested every few hours.
High pH is just as ineffective as low pH in your pool. If your swimming pool is experiencing high pH conditions and gets excessively high, the water becomes overly soft. Swimmers can develop skin irritation alongside dryness and red eyes. Too high a pH level can also destroy piping and pool water filter equipment.
The use of some chemicals like Shock chlorine, or Algaecides and even the natural effect of aeration can raise the pH in your pool water by gassing off Co2 and replacing the Co2 with Carbonic Acid which is then replaced with Bicarbonate Ion. This causes the ph in the swimming pool to fluctuate naturally.
If the pH level is above 7.8 then you can expect the water to become cloudy and to see scaling along the pool sides. Metal parts of your pool can also corrode, and vinyl linings may wrinkle if the water is too acidic
When water is too high a pH, it reduces the effectiveness of chlorine the pool chemical that kills bacteria and pathogens. Water with a high 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.
High pH in pools:
- Chlorine is around 50% less effective at pH levels over 8.2 in pool water
- Scaling from calcium deposits on pool surfaces and waterline
- Algae bloom likely
- Pool water may appear cloudy and dull
Water alkalinity is a measure of your water’s ability to neutralize acids. It’s an important part of balancing pH levels and is often called a “buffer” because it helps the water resist drastic changes in pH. Unbalanced alkaline levels can have an adverse effect on your hot tub’s appearance and even affect your skin.
Low alkalinity is the more serious of the two extremes. The alkalinity can cause rapid fluctuations in pH, because the water can’t as easily counteract the effects of acids, like acid rain or naturally occurring minerals.
Such an environment has a cascade of effects on your hot tub’s appearance: it can damage and erode its surfaces, while also corroding metal parts, and a perfect storm can result in unsightly stains. Low-alkaline spas also won’t be able to balance the amount of phosphates, which feed algae, resulting in water that is green.
To lower high alkalinity, you can use a pH reducer or muriatic acid chemical. Better yet, prevent mineral build-up and cloudy pool and spa water from the start with ProtectPlus, which inactivates damaging minerals.
For green water, use a shock treatment and work on restoring your hot tub’s overall pH balance. Once balanced, use a non-chlorine stabilizer like brominating tablets to control algae and bacteria.
As a general rule, always rinse off after your dip using warm water, not hot, and patting your skin dry instead of rubbing. Monitoring alkalinity in the water is an important part of hot tub maintenance. Unbalanced alkaline levels and pH can decrease the life expectancy of your hot tub and lead to costly issues down the road. Don’t skip this significant water maintenance step.
Effects of Lower Alkalinity in Pool Water-Spa Water
Total Alkalinity(TA) in swimming pool water is an important step in keeping stability and chemical working especially chlorine. Water contains ionic compounds that are Alkaline in nature. They act as a buffer for keeping the pH in your pool from slipping. Think of it as a muscle for pH. If lower Alkalinity is not balanced things go haywire fast! The pH of the pool level can get crazy.
Adjusting the alkalinity of pool water is an important first step for establishing a good chemical balance in your pool. Keep in mind that the lower the alkalinity, the more difficult it is to manage pH and disinfection rates in your pool. If your pool starts to test for a high pH, a quick response can save you some hassles.
High or low Total Alkalinity level is very closely related to pH, as it is a measurement of all alkaline substances in the pool water. Proper Alkalinity levels are a key factor in maintaining pH many describe it as being a “pH buffer.” Low Total Alkalinity levels cause rapid pH fluctuations, and high levels make pH difficult to adjust.
That said, it’s best to adjust one and then the other, not both at the same time. If Total Alkalinity is out of balance, address it first. The total Alkalinity level is brought back up to the proper recommended standard for swimming pools and spas which measured between 80-110 ppm Total Alkalinity (TA).
For a saltwater chlorine generator, most manufacturers recommend TA levels between 80-120 ppm. Maintaining the right balance of pH and Total Alkalinity is essential to keeping your pool water and spa water in good condition. If you can buy a good reliable test kit and don’t use test strips.
So make sure you understand the basics of each test you’ll be running and that your kit and reagents are fresh (they should have an expiration date stamped on each bottle) before Testing Pool Water.
The stronger the muscle or Total Alkalinity in water the less chance that pH moves up or down leaving that ideal range in the pH scale that is needed for the optimum level to keep your pool water sanitized and for chlorine to work properly. This pH and Alkalinity testing is critical for controlling your pool no matter the size or amount of water it holds.
Low Alkalinity in pools:
- Etching of pool plaster
- Vinyl liners become stiff and brittle
- Corrosion of metals in ladders, handrails, and heat exchangers
- Swimmer comfort issues, including burning eyes and dry skin
- Pool and Spa surface stains
- Rapid fluctuations in pH, known as “pH bounce”
Low alkalinity levels in hot tubs are a serious problem. But there are a few options to increase the levels. Here’s how to increase alkalinity in hot tub water.
The pollutants can range from sweat and even urine to a chemical residue that might be in your swimsuit and body oils. Mother Nature might also have something to do with a low alkalinity level. Rainwater is often more acidic than alkali, which means it could lower the alkalinity of your hot tub’s water. However, this wouldn’t be such an issue if you used a cover for your hot tub.
Finally, if you use chlorine tablets, they could also be causing a low alkalinity level. This is because chlorine tablets lower a hot tub’s pH levels.
Low Alkalinity in a Spa
- Skin irritation: The hot tub water becomes very acidic when the alkaline levels are low. Anyone soaking in the tub will find this very irritating for their skin, nasal passages, and eyes. It could even lead to respiratory distress.
- Tub damage: The damage that could occur depends on the materials of your hot tub. But it might include cracking, etching, staining, and delamination. If you use a vinyl cover, this could become brittle and stiff. It might include cracking, etching, staining, and delamination. If you use a vinyl cover, this could also become brittle and stiff.
- Green water: Algae blooms can be a serious issue to your spa or hot tub when alkalinity levels drop.
- Corrosion issues: Even if your hot tub is fiberglass, corrosion can still be an issue. However, it’s even more serious if your hot tub has a metal surface. It can also be detrimental to the internal workings of the pump and its filter. Corrosion issues could mean your pump and its filter will need to be replaced, which would be very costly.
- Fluctuating pH levels: When there is insufficient alkalinity in your hot tub water, it means the pH level will fluctuate wildly. This is known as the pH bounce. It happens because the water has an insufficient pH buffer.
Sodium bicarbonate or baking soda is commonly used to raise total alkalinity levels in hot tubs. You can buy various alkalinity increaser products, for example, Alkalinity Up or Alkalinity Increaser. Most branded alkalinity increasers are just baking soda marketed in an attractive bottle.
The benefit of baking soda is that it’s a very safe chemical to use. You can handle it without problems, pour it into your hot tub directly, and buy it from your local grocery store. The generic product will also be cheaper than a specially packaged alkalinity increaser.
You’ll also be pleased to learn that it will raise the alkalinity level but have minimal impact on the pH scale.
Baking Soda
Follow these steps:
Test your hot tub water using a digital tester, test strips, or testing kit.
Calculate the amount of baking soda needed to raise the total alkalinity level so that it’s a minimum of 80 parts per million.
Measure out the correct amount according to your calculations. Generally, you’ll need one tablespoon of sodium bicarbonate if your hot tub contains 100 gallons of water.
Wear goggles and rubber gloves to protect yourself.
Dilute the baking soda with water in a bucket. Make sure it’s completely dissolved.
Pour it into the hot tub and circulate the water for around 20 minutes.
Use another test strip to retest the water and, if necessary, repeat the retesting process.
Soda Ash Method
You can also use soda ash chemicals, otherwise known as sodium carbonate, to counter the low total alkalinity level in hot tubs.
The main difference with this method is that it will also act as a pH increaser and raise the pH level. This could be an issue if there’s nothing wrong with the pH reading at the time.
Follow these steps:
Test the hot tub water sample using test strips, a digital tester, or a testing kit. hundred gallons of water.
Protect yourself from chemicals by wearing protective eyewear and rubber gloves.
Add the required amount of soda ash to a bucket of water.
Use the skimmer handle to stir the solution until the ash has dissolved completely.
Pour the mixture directly into the home spa or swimming pool
Allow the tub to circulate the water for a few hours.
Use a fresh test kit to retest the water and repeat the procedure if necessary
What Causes Low Alkalinity in Pools?
- Rain can be acidic
- Increase in swimmer load
- Topping your pool off with H2O that has low alkalinity-after backwashing/wasting
- Chlorine-Chlorine is acidic
- High H2O evaporation-losing H2O can dilute TA
- Pool H2O agitation-H2O agitation increases the loss of CO2 …………………………………………………………………………………………Read more
What Causes High Alkalinity in a Pool?
- Cyanuric acid also called CYA or chlorine stabilizer raises TA
- Liquid chlorine (or ‘sodium hypochlorite) has a high pH
- High Alkaline fill water
- Soda ash-pH control
- Sodium carbonate-pH control
- TA rises due to excess hydroxides left behind by calcium and sodium hypochlorite .……………………………………………………………………………….. Read more
How to Adjust pH-Alkalinity in Water
Everything in water chemistry starts with alkalinity no matter what’s happening in your swimming pool whether it’s a concrete inground pool or a vinal above-ground swimming pool Total Alkalinity (TA) level has to be adjusted in the good operating range of 80-120ppm.
To bring down the pH level, use a chemical additive called pH reducer or pH minus. The main active ingredients in pH reducers are either adding muriatic acid or sodium bisulfate (also called dry acid). Reducers are readily available at pool supply stores, home improvement centers, and online.
Before you do-Remember you must bring down Alkalinity (TA) before you adjust the pH in the swimming pool water. If the pH of the pool is too low then use a ph increaser (sodium carbonate) to bring both pH levels up after the alkalinity is balanced in the pool.
Always start here with Alkalinity which is the basis of pool chemistry:
- Bring low Alkalinity up first in the pool
- Put pool filter on recirculate
- Add soda Ash, and sodium bicarbonate, better known as your household baking soda which is an effective product used to raise the alkalinity in your pool
- Evenly distribute by walking around the perimeter of the pool broadcasting the powder across the entire pool using gloves and goggles for protection
- Waiting for at least 6-8 hours for retesting the pool
- Once the total Alkalinity (TA) reading is 80-120 ppm in the pool
- Lower high pH level in pool targeting 7.4 with a pH-down product
The correct amount of a pH reducer depends on the water volume of your pool and its current pH level. High pH reducers usually come with a guide that takes into account the variables and calculates the proper amounts of pH reducer in steps to add to your pool water.
Whatever you do to raise alkalinity quite often affects the pH as well. However, pool owners commonly use aeration to deal with both pH and alkalinity imbalances. It will lower total alkalinity but not raise pH levels.
You circulate air into the water every time you need to raise the total alkalinity level in your home spa. Allowing some form of movement also helps. For example, you could buy an air pump and insert the hose into your hot tub to add airflow to the water.
How do you Fix Low pH and High Alkalinity?
- Recirculate pool with filter pump
- Calculate acid addition
- Add Muriatic acid diluted in a bucket of H2O & broadcast the acid around the pool
- Retest after 6-8 hours
- Once TA is 80-120 ppm
- Aerate the pool with a compressor or pump to mix the contents adding air
- Do this for 24-48 hrs. .………………………………………………………………………………………………………………………………..Read more
JimGalloway Author/Editor
