A pool is a great way to cool off while also providing other benefits such as increased strength and flexibility, stamina, and even balance and pasture.
However, if the pH of the pool is off, it can cause skin rashes, irritation, dry skin, and red, irritable eyes, to name a few. In this article, we will go over the causes of low pH in pools, how to raise it, and how to keep it in the appropriate range to keep your pool safe.
What does it mean to have a low pH?
Pools with low pH have a pH range of 0–6. This means that the pool is acidic, with 0 being the most acidic (and obviously the most dangerous) and 6 being slightly acidic. The appropriate pH of a swimming pool lies between the range of 7.4 and 7.8. This is so because anything below 7 is acidic, while anything above 7 is basic or alkaline.
The question you might want to ask is: “Is it bad to have a low pH?” and the answer is yes! As long as a pool can have a low pH, it can also have a high pH, but between the two irregularities, low pH is more undesirable.
Having a low pool pH is definitely bad for a pool as it gradually damages pool accessories such as ladders, railings, and light fixtures. It could also damage the pumps, filters, and heaters. It could even lead to damage to the pool’s tiles, stone, plaster, and concrete.
Also, swimmers are not unaffected by low pH. Low pH causes discomfort on the skin, leading to skin itching, rashes, red & burning eyes, and burning noses, to name a few. Judging from the discussion above, you can clearly conclude that it is not safe to swim in a pool with a low pH.
Before we dive into the major subject, it would be nice to clarify what the pH of water means for those that are new to it. If you already know what pH is all about, you can skip to the next section to understand the major causes of low pH in pools.
What is pH?
pH is simply the measure of how acidic or basic (alkaline) water is. A water’s pH has a range from 0–14, with 7 being neutral. A pH of less than 7 indicates acidity, and anything greater than 7 indicates alkalinity.
It is important to keep your pool pH balanced to avoid irregularities in your pool. Keeping the pH balanced does not only ensure that the water is clean, but also ensures that one enjoys all the benefits of the pool.
Not only that, but it also helps to save on the cost of repair of the pool’s essentials like the pump, heater, and the like. There are different ways of testing for water pH and some of them are:
- Water CO2 concentration: The concentration of carbon dioxide (CO2) dissolved in water has an impact on pH.
- Determination of overall temperature
- Concentrations of carbonate and bicarbonate
- The process of decomposition of organic materials
You might also want to ask: “How often should I test my pool pH?”. It is very important to check the pH of your pool as often as possible; as frequently as 2 to 3 times a week.
It is also very important to check your pool’s pH regularly to keep your water chemicals (especially chlorine) at their highest level of effectiveness.
What are the causes of low pH in a pool?
Having a low pH in your pool causes a lot of damage that is not cost-friendly, like etching and deterioration of plaster, concrete, and tiling of the pool.
It could also cause some discomfort for the swimmers, like irritation and itching of the skin, as well as burning eyes, and nose.
Now let us look into the factors that cause low pH in a pool. They include:
- Rainwater: Rainwater is acidic, and a particularly strong downpour can lower the pH of your pool. You might be thinking that rainwater functions as a pool diluter, but that is not always the case. Due to man-made pollution, rainwater is acidic, and as a result, your pool’s pH is bound to go low. Similarly, groundwater can be acidic, and any flooding into your pool might lower its pH.
- Human source: Releases from the bodies of swimmers like sweat, saliva, and urine are scientifically known to be acidic. When these are deposited into the pool, they are capable of lowering the pH of the pool.
- Pool water source: It is very possible that your local water supply that is supplying your pool water has a record of low water pH. When this water flows into your pool, the overall pH level of the pool will be affected. Endeavor to ask your local authority for a water report. That will help in knowing the next line of action.
- Chemical source: You might have tried to be your pool’s ‘good Samaritan’ after noticing that the pH was too high by adding too much pH reducer. The excessive addition will surely result in a drastic lowering of your pool’s pH. In addition, some chlorine tablets, such as Trichlor, have a pH of only 2.8. Bromine, too, has a pH of only 4. When you apply them to your pool, you already know what’s bound to happen!
How to test for the pH of your pool?
It is necessary to test the pH of your pool regularly as this will ensure that the pool is safe to swim in. This is because an unbalanced pH could create an environment that could abhor bacteria and algae growth.
There are many ways of testing pool pH; some of which are:
- Strip Testing: This is a fast and easy way to test the pH of a pool. All you have to do is dip the pH strip into the pool and compare the color the pH strip gives with the pH chart, which usually comes along with a pH strip when purchased.
- Electronic pH Tester: This method is fast, much more effective, and has a greater advantage than the strip method because it gives you an exact and specific result. The only con is that it is more expensive, but it is definitely worth it in the long run.
Another method used to test a pool’s pH involves using a pH kit, and this method definitely has to do with a lot of chemicals. Hence, the services of a professional are your best bet.
How to raise the pH level of your swimming pool
There are a couple of ways in which this can be done. However, one of the most common ways is by adding soda ash. Soda ash is a strong alkaline material that dissolves completely in water.
It works on the principle that a strong alkaline substance would neutralize an acid (in this case, an acidic solution). It is important to evenly distribute the soda ash across the entire pool and allow the water to circulate. Your pool’s pH has been raised with this simple method.
It is also possible to add more soda ash than required, and this will make your pool pH basic/alkaline. This is why it is important to calculate the amount of soda ash required, which usually should not exceed two pounds per 10,000 gallons of water.
There are a few other methods of increasing the pH, one of which is checking the total alkalinity of the pool. Total alkalinity is the sum of all the basic materials in the pool water.
Sodium bicarbonate is usually used to raise the total alkalinity of a swimming pool. It is important to only add about 1.4 pounds of sodium bicarbonate per 10,000 gallons of water.
Another method used to raise the pH of a pool is through aeration of the pool water. This method involves bubbling oxygen or air through the water. You should note that this method usually takes a few days, but it definitely gets the job done in the long run.
Why is the pH of my pool always low?
If you are wondering why your pool’s pH is always getting low even though you frequently fix it well. It could be due to natural factors like heavy rainstorms or simply due to improper use of chemicals.
It can also be a result of the pool being overused, especially if you are a regular pool party organizer.
Does chlorine cause low pH?
Ordinarily, having chlorine in your pool doesn’t affect the pH significantly, but having it in excess can be dangerous as exposure to high levels of chlorine can cause lung irritation, skin irritation, and eye damage, which are very bad.
High chlorine levels also decrease the pH of your pool water, making it acidic and corrosive, which could lead to the damage of some of your pool’s essentials.
You should note that the higher the acidity of the water, the greater the risk of corrosion. Corrosion can harm metal piping, equipment, and your pool’s surfaces (tiles, liners, concrete, etc.).
It can also harm pool accessories and anything else that comes into contact with the water in your pool.
What pool pH does chlorine work best?
The pH scale ranges from 0 to 14, with pH 7 indicating neutrality. Water is basic if the pH is greater than 7, and acidic if the pH is less than 7.
Pool water should have a pH of 7.4, which is the same as the pH of human eyes and mucous membranes. Chlorine disinfection is also good at pH 7.4, at which point we can say chlorine works best.
Can I shock my pool if its pH is low?
The answer is simply, “yes!” This is because having a low pH is one of the most suitable factors to successfully shock a pool. If your pool is tested and found to be basic, about half of your shock would be basic.
However, at a pH of about 7.2, over 90% of the shock would become active algae and bacteria killers.
Does chlorine pool shock increase pH?
Chlorine-based pool shock (Calcium Hypochlorite) has a high pH, and will normally raise the pH level of your pool water, as well as change your chlorine level. Chlorine-free shock has an unbiased pH, and won’t influence any of your pool substance levels.
How much baking soda does it take to raise pH?
Experts have revealed that, based on professional experience, 1.25 pounds of baking soda is necessary to elevate the PH level of a 10,000-gallon pool by 10 ppm.
In the same way, a 100,000-gallon pool would require 12.5 pounds of baking soda for its pH to be raised by 100 ppm.
Why should I add baking soda to my pool?
Baking soda, commonly known as sodium bicarbonate, has a pH of 8 and is naturally alkaline. When you add baking soda to your pool water, it raises the pH and alkalinity.
This helps your pool by improving its stability and clarity. Because of its basic nature, baking soda is the principal active ingredient in many commercial pool pH-raising products.
Is pH increaser the same as baking soda?
Baking soda (sodium bicarbonate) is an alkaline material that has a pH of 8. It is widely used to raise pH as well as total alkalinity. It is, in its own way, a pH increaser.
We can clearly say that all baking sodas are pH increasers, but not all pH increasers are baking soda. As a matter of fact, the majority of pH increaser products are little more than baking soda in nice packaging.
Do you need a high or low pH in a pool?
The pH of water ranges from 1 to 14. Lower numbers indicate acidity, while larger ones indicate alkalinity. Pool pH should be between 7.3 and 7.6 for optimum performance and the cleanest water, according to pool professionals.
You should endeavor to keep your pool’s pH balanced, as neither high pH nor low pH is beneficial to your pool. However, the latter is more dangerous than the former.