How to Bring pH Up in Pool: Mastering the Chemistry Behind Crystal Clear Water

Pool chemistry feels like alchemy sometimes. You're standing there with your test kit, watching those color-changing drops reveal that your pH has plummeted again, and suddenly you're thrust into the role of amateur chemist. Low pH in pools isn't just a number on a test strip—it's the difference between water that feels silky and inviting versus water that stings your eyes and slowly eats away at your expensive equipment.

I've watched countless pool owners struggle with this invisible enemy. The pH scale might seem abstract until you realize it's literally determining whether your Saturday afternoon swim feels refreshing or leaves everyone complaining about burning eyes. When pH drops below 7.2, your pool water becomes acidic enough to corrode metal fixtures, etch plaster surfaces, and turn what should be a relaxing dip into an uncomfortable experience.

Understanding the pH Puzzle

Let me paint you a picture of what's actually happening in your pool. The pH scale runs from 0 to 14, with 7 being neutral—like pure water. Your pool wants to live in that sweet spot between 7.2 and 7.8, though I personally aim for 7.4 to 7.6. Below 7.2, and you're in acid territory. Above 7.8, and you're dealing with scaling and cloudy water.

What throws many people off is how logarithmic this scale works. A pH of 6 isn't just "a little bit" more acidic than 7—it's ten times more acidic. This exponential relationship explains why small pH changes create big problems.

Rain, especially in areas with acid rain, can tank your pH overnight. Chlorine tablets, those convenient hockey pucks most of us use, are acidic by nature. Even heavy bather load—all those oils, sweat, and yes, urine—can push pH downward. I once tested a pool after a kids' birthday party and watched the pH drop from 7.4 to 6.8 in a single afternoon.

The Arsenal for Raising pH

When it comes to raising pH, you've got three main weapons in your chemical arsenal, and each has its personality.

Sodium carbonate, or soda ash, is the heavyweight champion. This white powder dissolves quickly and punches pH upward efficiently. I keep a 50-pound bag in my shed because it's the most direct route to pH correction. The stuff is aggressive though—add too much too fast, and you'll overshoot your target, creating a whole new set of problems.

Then there's sodium bicarbonate—good old baking soda. This gentler option raises both pH and alkalinity, making it perfect when both readings are low. It's like the Swiss Army knife of pool chemicals. Some pool stores will try to sell you "alkalinity increaser" for three times the price, but check the label—it's usually just baking soda in fancy packaging.

Borax deserves a mention too. This laundry aisle staple raises pH without significantly affecting alkalinity. I discovered this trick from an old-timer at a pool supply convention who swore by it. The 20 Mule Team stuff works just fine, though you'll use more of it compared to soda ash.

The Art of Application

Here's where theory meets practice, and where most people mess up. You can't just dump chemicals in and hope for the best. I learned this the hard way when I first started maintaining pools—created a localized hot spot of high pH that bleached a section of vinyl liner.

Start by calculating your pool volume accurately. That "about 20,000 gallons" estimate won't cut it. Length times width times average depth times 7.5 gives you gallons for rectangular pools. For kidney shapes and freeforms, you'll need to get creative with your measurements or use an online calculator.

Once you know your volume, the math becomes straightforward. For every 10,000 gallons, six ounces of soda ash typically raises pH by 0.2. But—and this is crucial—start with half the calculated amount. Pool chemistry isn't linear, and factors like temperature, alkalinity levels, and dissolved solids all play roles.

Dissolve your chosen chemical in a bucket of pool water first. Never add water to chemicals—always chemicals to water. I've seen the burns from doing it backward, and they're not pretty. Walk around the pool's perimeter, pouring the solution slowly with the pump running. This prevents concentration in one area and ensures even distribution.

Timing and Testing

Patience isn't just a virtue in pool chemistry—it's a requirement. After adding pH increaser, let your pump run for at least four hours before retesting. I usually wait overnight when possible. The water needs time to fully circulate and the chemicals need time to work their magic.

Morning testing gives the most accurate readings. The sun hasn't heated the water yet, and there's been no swimmer activity to skew results. I keep a logbook of my test results—sounds obsessive, but patterns emerge that help predict and prevent problems.

Digital meters provide more precise readings than test strips, though quality strips work fine for routine monitoring. Whatever method you choose, consistency matters more than perfection. Test the same way, at the same time, from the same spot.

The Alkalinity Connection

You can't talk about pH without discussing total alkalinity—they're dance partners in the pool chemistry waltz. Alkalinity acts as a pH buffer, preventing wild swings. When alkalinity drops below 80 ppm, pH becomes unstable, bouncing around like a pinball.

I think of alkalinity as the pool's shock absorber. Just as your car's suspension smooths out bumps in the road, proper alkalinity levels smooth out pH fluctuations. Maintaining alkalinity between 80-120 ppm makes pH management infinitely easier.

Sometimes you'll need to adjust alkalinity before tackling pH. If alkalinity is below 80 ppm, use sodium bicarbonate first. This raises both alkalinity and pH, though alkalinity increases more dramatically. Once alkalinity stabilizes, fine-tune pH with soda ash if needed.

Natural pH Drift and Prevention

Pools have personalities, and understanding yours saves chemicals and frustration. My own pool tends to drift acidic thanks to oak trees dropping leaves and our frequent summer thunderstorms. A neighbor's pool, identical in size but surrounded by concrete instead of vegetation, stays remarkably stable.

Cyanuric acid levels affect pH stability too. This chlorine stabilizer, while necessary for outdoor pools, can create a phenomenon called "pH suppression" at high levels. Keep CYA between 30-50 ppm for easier pH management.

Regular maintenance prevents dramatic pH crashes. I check and adjust twice weekly during swim season, catching small drifts before they become big problems. Think of it like changing your car's oil—regular small efforts prevent major repairs.

Troubleshooting Common Scenarios

Sometimes pH refuses to budge despite your best efforts. Usually, this points to extremely low alkalinity or high dissolved solids. In severe cases, partially draining and refilling the pool provides a fresh start. I've seen pools where years of chemical additions created such mineral buildup that water replacement was the only solution.

Cloudy water after raising pH often means you've precipitated calcium. The suddenly higher pH caused dissolved calcium to solidify. Running the filter continuously for 24-48 hours usually clears this up. Adding a clarifier speeds the process.

If pH keeps dropping despite repeated corrections, look for the source. Leaking chlorine feeders, overdosing with trichlor tablets, or even certain algaecides can suppress pH. One client's pH mysteriously dropped every Tuesday—turned out their lawn service's fertilizer overspray was the culprit.

The Economics of pH Management

Let's talk money, because pool chemicals aren't cheap. Buying in bulk saves significantly—a 50-pound bag of soda ash costs about the same as three 5-pound containers. Store chemicals properly though. Moisture turns soda ash into concrete-hard chunks.

Some pool owners chase perfect numbers obsessively, burning through chemicals and money. Unless you're dealing with specific problems, keeping pH between 7.2-7.8 is sufficient. That 7.5 target? It's ideal, not mandatory.

Consider the hidden costs of neglecting pH too. Acidic water destroys pool equipment prematurely. I've replaced heaters corroded by chronically low pH—a $3,000 lesson in the importance of water balance. Spending $50 monthly on chemicals beats replacing major equipment every few years.

Advanced Considerations

For those ready to go deeper, pH management connects to every aspect of pool chemistry. The Langelier Saturation Index uses pH, alkalinity, calcium hardness, temperature, and dissolved solids to predict water's tendency to scale or corrode. It sounds complicated but becomes intuitive with practice.

Salt water pools present unique pH challenges. The chlorine generation process naturally raises pH, requiring regular acid additions to compensate. Some salt system owners add acid weekly, others install automated pH controllers. Both approaches work—choose based on your involvement level and budget.

Indoor pools face different pH dynamics than outdoor pools. Without rain dilution or sun-driven chemical reactions, indoor pool pH tends toward stability. However, poor ventilation can create carbon dioxide buildup, dropping pH unexpectedly.

Final Thoughts on pH Mastery

Managing pool pH becomes second nature with practice. What seems overwhelming initially transforms into a simple routine. I barely think about it now—test, calculate, add, circulate. The process takes minutes but provides hours of swimming enjoyment.

Remember that perfect water chemistry isn't about hitting exact numbers—it's about maintaining safe, comfortable swimming conditions. Your pH might run slightly high or low based on local conditions, and that's okay if swimmers are happy and equipment stays protected.

Pool care connects us to basic chemistry principles in tangible ways. Every time you successfully raise pH, you're applying scientific knowledge to solve real problems. There's satisfaction in transforming problematic water into a crystal-clear oasis.

Take pride in mastering this essential pool skill. Your swimmers might never thank you for perfect pH, but they'll certainly complain about burning eyes and itchy skin when it's wrong. In pool care, no news is good news—and proper pH management keeps the complaints at bay.

Authoritative Sources:

Centers for Disease Control and Prevention. "Disinfection & Testing." CDC.gov, U.S. Department of Health & Human Services, 2023, www.cdc.gov/healthywater/swimming/residential/disinfection-testing.html

Griffiths, Tom. The Complete Swimming Pool Reference. 2nd ed., Sagamore Publishing, 2003.

Lowry, Robert W. Pool Chemistry for Service Pros. Lowry Consulting Group, 2019.

National Swimming Pool Foundation. Pool & Spa Operator Handbook. National Swimming Pool Foundation, 2022.

Tamminen, Terry. The Ultimate Guide to Pool Maintenance. 3rd ed., McGraw-Hill, 2007.

Taylor Technologies. "Pool & Spa Water Chemistry." TaylorTechnologies.com, Taylor Technologies Inc., 2023, www.taylortechnologies.com/en/page/231/pool-spa-water-chemistry

United States Environmental Protection Agency. "Drinking Water Regulations and Contaminants." EPA.gov, 2023, www.epa.gov/sdwa/drinking-water-regulations-and-contaminants

Williams, Roy. Aquatic Facility Operator Manual. 4th ed., National Recreation and Park Association, 2021.