I can see you now. You are staring at the test kit results and feel confused about the further process of raising the pH in the pool. Moreover, you might wonder how low pH can affect the pool.
Don’t panic! Issues with pH are easy to solve with simple and affordable chemicals or even without them.
Here, I don’t propose you a universal and one-way solution to raise pool pH, because there is no such thing. I am convinced that those who propose only one, barely understand pool chemistry.
In this article, I teach you about 3 effective methods to increase pH in the pool according to the existing chemical balance. We even learn how you can raise pH naturally and without any chemicals. In addition, I will debunk the myths about the use of baking soda and the effects of low pH on the pool.
If the pH is too high, the best way to lower it is with muriatic acid. Check out a guide on how to decrease pH in the pool?
pH is usually the first thing you check while testing the water. pH means ”potential of hydrogen” or “power of Hydrogen”, in other words, it evaluates the concentration of Hydrogen ions in water. It is used to measure how acidic or basic the liquid is. When the concentration of Hydrogen increases, the solution becomes more acidic, so the pH decreases.
pH ranges from 0 to 14, where 0 is the most acidic and 14 is the most alkaline. The pH of 7 is neutral.
The recommended value of pH for the pool is 7.2-7.6. When the pH gets too low it may influence chlorine efficiency and lead to corrosion of the pool. When the value is above 7.8 you might see the scaling on the surfaces, cloudy water, and skin and eyes irritation.
😀 Fun fact: Only water-based solutions have pH. Neither oil nor ethanol extracts have pH value.
pH is often mixed with total alkalinity (TA). These parameters are not the same but are highly interconnected. For this reason, you need to know both pH and TA before deciding on a method for raising pH.
Total alkalinity shows the concentration of all alkaline compounds in water. These substances can either attract or release Hydrogen ions. This creates a buffer in water that resists a decrease in pH.
When the concentration of Hydrogen ions increases (the solution should become more acidic), alkaline compounds absorb these ions and “neutralize” them. As a result, the overall amount of Hydrogen ions doesn’t increase, so the pH remains the same.
Bicarbonate, carbonate, and hydroxide are major contributors to the total alkalinity (TA). Total alkalinity is measured in parts-per-million (ppm) and the standard range is from 80 to 120 ppm.
💡 Useful facts
Total alkalinity and pH are in tight connection. In most cases, if you raise pH, you increase TA, and if you decrease TA, you decrease pH. So you need to know both TA and pH to manage the pool effectively.
The higher TA is faster and the higher pH raises naturally. For example, if the total alkalinity (TA) is 80 ppm and water temperature is 80°F (26.6°C), the pH will raise naturally to 8.32!
When you add chemicals such as washing soda/soda ash to raise pH, you simultaneously increase total alkalinity.
High TA requires more acid to decrease pH and you will need to add it more frequently to stabilize pH. As a result, you will spend more on chemicals.
You need to do two important things before deciding on the method to increase pH.
Ok, I am sure you have already done it (why else you are here). Just in case you didn’t do it, you need to determine pH and total alkalinity (TA). If you wonder how to do it right, follow our complete guide on testing water in the pool.
Ideal pH: 7.2-7.6
Ideal TA: 80-120 ppm
The TA amount will determine the correct method to use in your situation.
❗ If your pH is lower than 7.0, aeration will take a long time. If TA allows, firstly use Borax to increase pH to 7.0 and then use aeration to adjust it.
You should dose every chemical following the total volume of the pool. If cannot find this information in the documentation for the pool, you can use the formulas below:
Length (ft) x width (ft) x average depth (ft) x 7.5 = volume (gallons)
Radius squared (ft) x average depth (ft) x 3.14 x 7.5 = volume (gallons)
Check our article on calculating volumes of the pool.
Borax is a commonly used chemical to raise pH. They can do it fast and increase TA only a little. If your TA is already high, Borax is your solution. It is easy to use and it raises pH without rapid changes, so it is hard to make a mistake.
💡 Useful fact: Borax has many names: Sodium borate, Sodium tetraborate, and Disodium Tetraborate. Look for these compounds while buying chemicals to increase pH. You can find borax in the grocery store near products for laundry.
❗ Don’t forget to test the water before adding Borax
Soda ash aka Washing soda or pH Up is the most well-known chemical to increase pH in the pool. It raises both pH and TA.
💡 Bear in mind! Soda ash (sodium carbonate) is NOT a baking soda (sodium bicarbonate). The compounds are different and affect water chemistry differently!
📌Pro tip! If you use trichlor to stabilize the chlorine is also better to use soda ash to increase pH than borax, because trichlor decreases both pH and TA.
❗ Don’t forget to test the water before adding chemicals
Amount of soda ash = (Points to add/2)×6 oz |
📌 Pro tip: Don’t exceed 15 pounds per 5 gallons. Otherwise, it can be difficult to dissolve the salt.
Aeration is a natural way to increase pH without affecting TA. The only drawback of this method is time. Compared to Borax or soda ash, it usually takes more than one day of aeration to significantly change pH.
Because of the time factor, it’s better to use aeration only if the pH is not less than 7.0.
The aeration process is straightforward.
While you might find threads about adding baking soda to raise pH on popular forums such as Quora or Reddit, I must warn you from doing so.
As I said before, people usually mix baking soda (sodium BIcarbonate) with soda ash (sodium carbonate). The compounds are not the same and act differently for pool chemistry.
NaHCO3 ≠ Na2CO3 |
You should remember that baking soda influences total alkalinity and has minor effects on pH. The pH of the sodium bicarbonate solution ranges from 8.3 to 8.6 which is not enough to shift the pH of the pool significantly.
If the TA gets too high, it becomes hard to low pH, as TA works like a buffer and resists the change. Also, the pH increases faster and it is likely to become out of range. If the pH is higher than 7.8, you may experience cloudy water and scaling.
In a nutshell: You shouldn’t use baking soda to increase pH.
While going through many articles you might find that low pH leads to negative consequences for health and pool maintenance. Common thoughts include:
I am happy to inform you that most of these statements are not true or partly false. Below we debunk some of them with facts.
⬇️ Decrease efficiency of chlorine
This is a myth and a fact at the same time. If you don’t add cyanuric acid (CYA) to the water, then the level of active chlorine strongly depends on the pH.
However, when you add cyanuric acid (CYA) for chlorine stabilization you almost demolish the impact of pH on chlorine form.
👀 Skin and eye irritation
Nobody wants to be itchy or see skin irritation after swimming in an acidic pool. But the truth is that our skin surface is a little acidic and its pH ranges from 4 to 7. So swimming in a little acidic water cause no harm [1].
As for the eyes, their normal pH is around 7.1 [2], but this is not the pH that causes major eye irritation and redness. Chlorine causes the biggest damage to the eyes. It dehydrates the eyes and, breaks tear film that protects the eyes from infections.
⚠️ Damage to the pool
This is the fact. Maybe you won’t notice severe effects with a pH of 7.0, but as more acidic the water becomes more damage it makes to the pool. Acidic water causes corrosion of pump, concrete, and metals. It also makes the surface of tiles rougher, which promotes algae growth
While deciding on the method of raising the pH, you need to test the pool for pH and total alkalinity as these factors are interconnected. While pH stands for Hydrogen concentration, the total alkalinity describes how resistant the pool is to the decrease of pH.
There are 3 methods to choose from: adding borax, adding soda ash, or aeration. Borax is good in raising pH and has a little effect on tidal alkalinity. Soda ash adds to both pH and TA. Aeration requires no chemicals and increases pH naturally. You should use aeration if the pH value is not lower than 7.0.
The best way is aeration. This method doesn’t require chemicals at all. Borax is another solution as it affects total alkalinity a little.
This is not the best idea, as backing soda increases total alkalinity more than pH. The better solutions are borax, soda ash, or aeration.
Aeration is the best method to raise pH naturally. You should disturb the water with jets, fountains, waterfall, etc to release CO2.
The fastest way is to use borax or soda ash. Just calculate the needed amount, and weight, dissolve it in the bucket of pool water, and pour it into the pool. With a pump on you can see a pH shift in 30 minutes.
Use soda ash. It increases both pH and total alkalinity.
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