A swimming pool with a low pH leads to corrosion, equipment damage, and skin irritation. Most swimming pool chemicals work best in the optimal pH range (7.2 to 7.8). Maintaining and adjusting your pool’s pH is an inevitable part of the process.
Fortunately, it’s quite easy to increase the pH and prevent long-term problems.
To raise the pH level in a pool, follow these steps:
- Test the pH and alkalinity
- Add soda ash to the pool
- Wait for 24 between treatments
- Remove the debris from your pool
- Consider replastering the pool
- Don’t swim in the pool until the pH goes up
- Increase the alkalinity
- Heat the swimming pool
- Choose the right type of chlorine
- Monitor your chemicals’ pH
- Cover the pool when it’s raining
- Consider adding a water feature
Throughout this post, I’ll show you everything you need to do to test and increase your pool’s pH. It’s important to work in small increments, so let’s dive into the step-by-step process below.
1. Test the pH and Alkalinity
Always test your pool’s pH and alkalinity before adjusting them. The alkalinity and pH go hand-in-hand. When you increase the alkalinity, the pH goes up (and vice versa). The same rule applies to reducing the pH or alkalinity. It’s important to adjust both of them rather than solely relying on the pH to increase them both.
You can test your pool’s chemistry with test strips or liquid drops. I’ll show the pros and cons of both, along with product suggestions to help you make the best decision for your swimming pool.
Liquid Pool Test Kits
Liquid pool test kits are typically the top choice for pool professionals. I recommend choosing these drops if you prefer a longer shelf life, quicker results, and better accuracy. However, they tend to cost a bit more than the test strips.
The Taylor Swimming Pool Test Kit is my personal favorite because it includes tests for alkalinity, pH, hardness, bromine, and many other chemicals.
You just need to fill both vials with pool water and add the recommended amount of drops to find out your pool’s chemical makeup. Each kit includes enough drops for two to three swimming seasons.
Pool Chemical Test Strips
Pool test strips are a popular choice for new pool owners and those on a budget. They’re much easier to use than the aforementioned drops, but they don’t have quite the same shelf life.
Each strip contains several chemical readings to help you adjust your pool’s chemistry.
The JNW Pool and Spa Test Strips monitor the pool’s chlorine, alkalinity, pH, cyanuric acid, and more. Each bottle includes 100 test strips that need to be stored in a cool, dry place.
Dip a strip into the water and line it up with the bottle to know which chemicals need to be adjusted. You’ll also receive a free smartphone app to track your pool’s progress.
2. Add Soda Ash to the Pool
Soda ash is the primary ingredient in increasing your pool’s pH. While it slightly elevates the alkalinity, it’s typically recommended for a low pH since it’s rapidly effective.
Soda ash is found in most pool stores, online retailers, and box chain stores. However, big chain stores often dilute their soda ash, so make sure you look for fillers.
In the Swim’s pH Increaser is made of 100% filler-free soda ash. Each 25-pound bucket contains enough soda ash to increase the pH of the biggest pools around. All it takes is one pound of soda ash to raise the pH of a 10,000-gallon swimming pool. This soda ash is also available in 10-pound and 50-pound bags.
Any pool professional will tell you that soda ash is an integral part of owning a pool. Your pool’s pH can drop from all sorts of things, so it’s important to have a bucket or bag of soda ash ready to go.
Keep these tips in mind when using soda ash in your pool:
- Circulate the pool pump until the cloudiness goes away. Soda ash is a granular chemical that can cause slight cloudiness. Running the pump will limit the cloudiness and prevent the soda ash from settling on the bottom of the pool. Many manufacturers list pump circulation as a required step.
- You have to remove the pool cover when adding soda ash; Otherwise, it can get stuck on the cover. Pool covers limit chemical evaporation, so you can replace them once the soda ash dissolves in the water. 100% soda ash dissolves much quicker than filler-packed soda ash products.
- Never add soda ash and muriatic acid at the same time. Not only do they conflict with each other on the pH scale, but these chemicals can cause bubbling and severe chemical burns. They can also corrode the gunite, vinyl, pebble, or fiberglass in your swimming pool.
3. Wait 24 Hours Between Treatments
In my experience, it’s best to wait a full day between chemical treatments.
Alkalinity and pH adjustments take a while to affect the swimming pool. After all, you’re adding a couple of pounds of granules to a massive body of water. You can suddenly and drastically increase the pH. If that happens, you’ll have to use muriatic acid to reduce it.
Here’s what happens if you add the soda ash too soon after the initial treatment:
- Your pool will get incredibly cloudy, so you’ll have to clean the filter multiple times. Never stop running the pump until the cloudiness goes away. Keep an eye on your filter’s pressure gauge and clean it once it exceeds 20 PSI.
- The pH can get too high, which will lead to stains on the liner or gunite, poor chemical retention, and calcium buildup. You’ll also have to add liquid acid or dry acid to reduce the pH, which takes more time and costs more money.
- Adding too much soda ash will likely raise the alkalinity to extremely high levels. A highly alkaline swimming pool pulls the pH even higher, requiring more chemical adjustments. Furthermore, it will make it easier for algae blooms to grow.
As you can see, waiting 24 hours is tedious but necessary. That’s why it’s best to make pH adjustments several days before a big pool party.
You might have to make multiple changes if you don’t increase it enough (or it gets too high). Give yourself a time buffer to adjust the pH, alkalinity, and other chemicals that evaporate during the process.
4. Remove the Debris From Your Pool
Your swimming pool will inevitably get all sorts of natural and artificial debris in it. For example, local plants, pests, pets, hair, oils, dander, and other debris can alter the pH.
This debris also uses the free available chlorine (FAC), converting it into chloramine (unusable chlorine). This process increases the likelihood of algae blooms and stains.
Most plants and soil have a slightly acidic pH, so they need to be removed from the pool as quickly as possible. Nothing is quite as bad for a pool’s chemistry as a squirrel laying at the bottom of the liner or a bunch of dead fruit resting in the skimmer basket.
Follow this quick method to clean the debris and prevent it from reducing the pool’s pH:
- Empty the pump basket and skimmer basket daily while adjusting the pH or alkalinity. Make sure you turn off the pump to prevent the strong suction from holding these baskets. The debris quickly traps itself and instantly affects the pH.
- Use a pool vacuum to clean the bottom of the pool. Pool vacuums work by suctioning the debris and algae out of the pool, preventing them from affecting the pH, alkalinity, and chlorine. You should vacuum your swimming pool one to two times weekly.
- Use a mesh pool net to remove excess debris from the pool’s surface. The Sunnyglade Swimming Pool Mesh Net is 17.5 x 11.8 inches, which is more than enough to grab all of the leaves, dirt, bugs, and other debris in the pool. This budget-friendly net is ultralightweight, easy to maneuver, and fits most universal telescoping poles.
Removing the debris from your pool will make it safer, healthier, clearer, and less expensive to maintain.
5. Consider Replastering the Pool
Pool plaster needs to be replaced every two to three decades. You can replaster the surface, wash away the top layer, or refinish it with pebble liners.
Pool plaster corrodes due to long-term wear and tear, unwanted acidity, low alkalinity, and chemical corrosion. Replastering the pool can increase the pH because of the calcium found in the new plaster layer.
Replastering a pool is one of the most expensive treatments for low-pH problems, but it’s quite effective. You should only replaster it if the gunite is older than twenty years, if it has holes and pockets, or if the old plaster flakes into the pool.
Here’s what you should know about replastering a pool to increase the pH:
- Plaster contains quite a lot of calcium, which naturally increases the pool’s pH. You’ll have to add muriatic acid or dry acid for a month or two following the replastering process; Otherwise, the new plaster will stain and grow calcium deposits.
- The new plaster layer needs to be brushed, which can make the pool cloudy. Make sure you clear up the cloudy pool by running the pump as often as possible. Your filter should be cleaned when the pressure gauge gets too high to prevent plumbing and mechanical problems.
- Acidic water can quickly ruin a brand-new layer of plaster. It’s essential to monitor and adjust the pH, alkalinity, hardness, and other chemicals immediately after replastering a swimming pool. You’ll likely have to add calcium to the pool to rejuvenate the plaster until the pH corrects itself.
Replastering the pool might seem like an extreme measure to fix the pH and alkalinity. However, it’s an effective way to restore your pool and regulate its chemistry.
6. Don’t Swim in the Pool Until the pH Goes Up
People bring all sorts of debris and phosphates into the pool that instantly affect the pH. For example, hair, oils, dead skin cells, and many other things we bring into the water are acidic. They also encourage algae blooms, cloudiness, and similar unwanted side effects.
You shouldn’t let people or pets swim in the pool until you’ve corrected the pH. Not only is it bad for the chemical makeup, but it’s also dangerous to swim in concentrated soda ash and muriatic acid. These harsh chemicals can cause burns, irritation, discomfort, and so on. Wait until the chemicals are dissolved, and the water is clear before swimming in the pool.
Pro-tip: If a person or pet gets in the pool right after adding soda ash or alkalinity up to the pool, spray them with a garden hose and follow it with a shower using soap and warm water. These chemicals have to be removed to prevent the previously mentioned burning, itching, and discomfort. Luckily, soda ash isn’t as harsh on the skin as muriatic acid.
7. Increase the Alkalinity
Your pH is affected by the alkalinity and vice versa. You can raise the pH significantly, but a low alkaline level will quickly make the pool acidic again.
How Stuff Works recommends adjusting the pH and the alkalinity right after one another for the best results. Not only will you prevent adverse effects, but you’ll also help the chlorine work more efficiently.
Pool Mate Alkalinity Increaser is a 25-pound bucket that has enough granules to elevate and maintain your swimming pool’s alkalinity throughout the year. They include a helpful chart to show you exactly how much of the product your pool needs to be between the recommended range.
Consider these factors when increasing the pool’s alkalinity:
- Your pool’s alkalinity should be between 80ppm to 120ppm. This ideal range works to promote a healthy pH between 7.2 to 7.8. Most pool chemicals work best when the alkalinity is maintained, so it’s a crucial (and often overlooked) portion of adjusting a pool’s chemicals.
- Most alkalinity increasers will increase the pH, too. Keep this tip in mind when adding the product. Your soda ash can increase the pH to 7.2, then the alkalinity increaser can boost the alkalinity and pH to the middle of the previously mentioned range. Never add too much alkalinity increaser, or the pH will skyrocket.
- Much like the soda ash, any alkalinity increaser will make the pool look cloudy. Circulating the pump will get rid of the cloudiness and evenly dissolve the chemicals. Many alkalinity boosters are made with baking soda, so they can be a bit abrasive if they settle on the bottom of the pool.
If there are two steps to take out of the article, they should be to add soda ash and increase the alkalinity. These instructions are irreplaceable and always required to maintain the pool’s pH.
8. Heat the Swimming Pool
Home Depot claims you can aerate the pool by heating it to increase the pH. Aeration is the natural process of adding air molecules to the water. What better way to aerate the water than to increase the heat and loosen the molecules? It’s quite easy, especially if you have all the equipment and tools required.
There are many ways to heat a swimming pool. However, not all of them are effective when it comes to increasing the water’s pH. I’ll provide some must-know facts below.
- Gas and electric heaters offer the quickest way to heat the pool. You can raise the pH by a couple of points, but you’ll still have to add soda ash and an alkalinity booster. This step simply expedites the process.
- While covering the pool is great for heating the water, it’s not the best choice for influencing the pH. Most pool chemicals need complete circulation, which is interrupted by the cover. The same issue applies to solar rings and liquid solar covers.
- Natural evaporation can affect the pool’s pH because it requires you to add water. Most well water and garden hoses have a slightly high pH. You could dilute the acidic water by draining the pool through evaporation and filling it with fresh water.
Pro-tip: Heating the pool will likely cause chemical loss, including reduced chlorine levels, algaecides, cyanuric acid, etc. You’ll have to add water to the pool if it drops below the skimmer basket to prevent air from getting into the plumbing.
However, the water can increase the pH and alkalinity. I suggest testing your hose water or well water before filling the pool.
9. Choose the Right Type of Chlorine
Chlorine products have varying pHs. Choosing acidic chorine will lower the pH and alkalinity, whereas adding high-pH chlorine will boost these factors. Pool owners often neglect to monitor their chlorine’s pH because the adjustments are incredibly slow and hard to notice until it’s too late.
So, how does each type of chlorine affect the pool’s pH?
Liquid Chlorine Has a High pH
Most store-bought liquid chlorine has a pH between 11.0 to 13.0. Always ask the store what their liquid chlorine’s pH is because many of them contain fillers. Your liquid chlorine should contain at least 10% chlorine since the rest of it will be water and other additives. A higher chlorine concentration often means a higher pH.
Powder Chlorine Increases the pH
Powder chlorine has a similar pH range as liquid chlorine. It often sits between 10.0 to 12.0, but it can be slightly higher. Much like the liquid variant, a higher concentration of chlorine results in a higher pH. Powder chlorine is often made of calcium hypochlorite, so it’ll slowly increase your pool’s calcium levels.
Chlorine Tablets Lower the pH
Unlike the other two main chlorine variants, chlorine tablets are incredibly acidic. Their pH often sits between 2.0 to 4.0, making them some of the most acidic chemicals in the pool. They contain cyanuric acid, which is used to reduce chlorine evaporation.
These tablets are so acidic that people often use them to remove algae stains. Thankfully, you can swim with chlorine tablets in the pool.
Having too much chlorine in the pool will undoubtedly affect the pH. You might have to lower the chlorine level to prevent unnecessary pH and alkalinity adjustments.
It’s never a good idea to overload the pool with chlorine unless you’re getting rid of a massive algae bloom.
10. Monitor Your Chemicals’ pH
Everything that goes into your pool affects the acidity. Anything from the people to the chemicals and debris in the water can alter the chemistry.
You should know everything that enters the pool and decide if you need to remove or adjust it. Many pool chemicals rely on acidity to reduce the chances of encountering an algae bloom.
Here’s a list of which chemicals can raise and increase the pH drastically:
- Chlorine tablets lower the pH
- Chlorine powder and liquid chlorine raise the pH
- Most algae preventatives and algaecides reduce the pH
- Calcium hardness increases the pH and alkalinity
- Pool salt increases the pH
- Cyanuric acid raises the pH in its concentrated form, but not in chlorine tablets
- Soda ash and baking soda increase the pH and alkalinity
- Muriatic acid and dry acid decrease the pH and alkalinity
- Phosphate removers typically increase the pH, but some of them lower it
Other chemicals that can influence the pH include pool clarifiers, liquid solar covers, and bromine. It’s important to ask the manufacturer how these products affect the pH since it varies on a case-to-case basis.
Some pools are destined to have a high or low pH, so you’ll have to fight it throughout the year. Covering the pool will suppress natural pH adjustments, but the chemicals you add will always have an effect.
For example, fiberglass pools are almost always acidic due to the low-pH makeup of the fiberglass.
However, gunite and plaster pools are usually basic (which means they have a high pH). Vinyl pools have varying pHs, depending on the concentration of the materials in the pool liner.
11. Cover the Pool When It’s Raining
Solar covers and winter covers are some of the best and most popular tools for preserving your swimming pool’s chemicals.
These winter covers and solar covers work by trapping the sun’s UV rays, reducing heat loss, and preventing anything from getting into the water. However, the cover needs to be big enough to overlap the edges of the pool for maximum benefits.
Here are three reasons covering the pool helps you increase the pH:
- Rainwater is often acidic, which quickly lowers the pool’s pH. Most pool covers wick away the rainwater, helping you maintain the pool’s pH and alkalinity. Furthermore, the rain contains phosphates for algae to eat and spread. You should always cover your pool when it rains unless you want to lower the pH.
- Wind typically brings all sorts of debris into the water. Most plants and animals contain low-pH debris that you’ll have to counteract with soda ash and baking soda. If you want to prevent costly chemical problems, it’s best to throw the pool cover over the water when it’s windy outside.
- Covering the pool during a rainy day prevents the soda ash and alkalinity booster from getting diluted. Too much rainwater will fill the pool and get rid of most of the pH boosters you recently added. However, this cycle isn’t much of an issue 24 hours after adding these chemicals.
If you want to increase your pool’s pH on a sunny day, steer clear of pool covers and opt for direct sunlight, evaporation (and refilling the pool), pool heaters, and aeration. Speaking of which, I’ll dive into how you can aerate the water with the unique features below.
12. Consider Adding a Water Feature
Water features are some of the most exciting parts of owning a swimming pool. These features range from waterfalls to jets and more. You can connect an in-ground pool to a spa with jets or a center water volcano to aerate the water. Anything that moves the water above the pool’s surface is excellent for aeration.
So, how does aeration work, and why does it increase the pool’s pH?
According to CPO Class, aeration works by outgassing the carbon dioxide molecules in the water, thus raising the pH.
Most water features create a lot of pressure that forces the water through the air above the pool. Once the air molecules interact with the pressurized water, the water aerates, and the pH increases.
The good news is that you don’t need an expensive bronze lion statue spouting a massive waterfall to aerate the pool. You can install small jets, add a few floating water fountains, or hire a professional to install a bubbler for your connected spa.
Pro-tip: While aeration increases the pH, it’s not enough to reduce extreme acidity. You still need to add soda ash, but the aeration process will make it much easier to maintain balanced pH levels. Furthermore, it can help with the alkalinity levels, so you don’t have to add as many chemicals to the pool once you make the necessary corrections.
Jonah has worked for several years in the swimming pool industry installing and repairing equipment, treating pools with chemicals, and fixing damaged liners. He also has plumbing and electrical experience with air conditioning, ceiling fans, boilers, and more. When he’s not writing for Temperature Master, he’s usually writing for his own websites, LawnCareLessons.com and DIYByHand.com.