In some of the previous articles, we discussed how to either raise the pH or alkalinity of pool water. But sometimes, both pH and alkalinity might be low at the same time. In such a situation, how do you raise both parameters at the same time?
Before we go further it is important to remember that the recommended pH range for your pool is 7.2 – 7.8 while that of the alkalinity is 80 ppm – 120 ppm.
Though there are a lot of pH and alkalinity increasers out there, our focus in this article is on possible home remedies to raise the pH and alkalinity of your pool. Many pool owners prefer natural compounds like baking soda and soda ash.
Baking soda and soda ash are natural compounds that can be used to increase the pH and alkalinity values of pool water. Baking soda is used to raise alkalinity, while soda ash is used to increase pH levels.
As you might know, anything that affects pH will probably affect alkalinity. This means that adding baking soda to raise the alkalinity of your pool water can affect the pH value of the water as well. Soda ash also does the same by impacting the alkalinity levels.
This, however, has caused a lot of confusion among pool owners. Some find it difficult to differentiate between their particular functions. Let’s be clear about that now;
- When raising the alkalinity of your pool water, use baking soda because it increases the alkalinity and has little impact on the pH.
- For the pH increase, use soda ash since it greatly increases pH more than baking soda and has an almost lesser effect on the alkalinity.
This means that you need a lesser quantity of baking soda (sodium bicarbonate) to raise alkalinity and a lesser quantity of soda ash (sodium carbonate) to raise pH.
Well, why is it like that? Because soda ash has a higher pH value than baking soda, at about 11.4 and 8.3 respectively. So you need a greater quantity of baking soda to do what a small amount of soda ash will do to the pH.
For instance:
To raise the pH of 10,000 gallons of pool water from 7.2 to 7.6, you need to add about 21 lbs of baking soda. But adding such an amount would raise the total alkalinity to about 150 ppm. That is too high for a pool.
But if you are using soda ash, you only need about 12.2 ounces to raise the pH of 10,000 gallons of pool water from 7.2 to 7.6. However, such an amount will only add about 10ppm to the overall alkalinity.
What causes low pH and alkalinity in a pool?
Several factors can cause the alkalinity or pH levels of water to decrease. Knowing some of these factors can help you manage your pool and prevent low alkalinity.
Some of the factors that are common among pool owners are:
Rainwater: Rainwater has a pH value of about 5.0-5.3. Since it’s acidic, a particularly strong downpour can lower the pH of your pool. Due to the pollutants in the atmosphere, rainwater is acidic. As a result, your pool’s pH is bound to go low. Similarly, groundwater can be acidic, and once it enters your pool, it might lower its pH.
Human source: Releases from the bodies of swimmers like saliva, sweat, and urine are scientifically known to be acidic. When these substances are deposited into the pool and accumulate, 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. You can as well test the water by yourself.
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!
What happens if pH is too low in a pool?
Having a low pH, as we discussed, is not good. It can affect the pool in various ways and also affect the swimmers’ health.
Having a low pH in your pool means that the pool water has become acidic. As we learned in high school science, acidic water can corrode many materials, including metals and tiles.
This implies that low pH can cause corrosion to different pool equipment, including the pool surfaces.
There are other ways low pH can impact negatively on the pool and swimmer’s health. Some of these negative effects are listed below.
Affects disinfectant: low pool pH is not good for your pool chlorine disinfectant. It usually renders it ineffective. This means that once the pH of your pool water becomes low, the sanitizer becomes less effective. As a result, microbes and other contaminants can easily enter the pool water.
Corrosion: we have already discussed this. Acidic pool water can corrode the pool surfaces and tiles. It can cause etching on the surfaces of pool equipment and can result in stains on the walls.
Eye and skin irritation: when you enter your pool and notice some burning sensations on your skin and eyes, know that the pH of the pool water is probably low.
Prolonged exposure to such an acidic medium can affect the eyes badly and cause skin reactions. So, it’s best to always avoid using a pool with a low pH.
Cause cloudy pool water: if the sanitizer becomes ineffective, the pool can easily get saturated with pollutants. These pollutants, coupled with stains from acidic corrosion, can cause cloudy pool water.
Is it safe to swim in a pool with low alkalinity?
It is never safe to swim in a pool with low alkalinity. Once the alkalinity of your pool becomes low, the sanitizer stops functioning effectively. This impacts the water chemistry and the healthy state of the pool water.
With ineffective sanitizer, your pool is bound to be contaminated with microbes, some of which might be detrimental to your health.
Moreover, acidic pool water can irritate the skin, nose, and eyes. So, anyone with respiratory health issues should do everything possible to not enter a pool with low alkalinity and/or pH.
Can a pool have low pH and low alkalinity?
Yes, once the alkalinity of your pool becomes low, it will affect the pH of the water. The pool pH is probably going to be low because alkalinity and pH move in the same direction on the scale.
So, it is very much possible to have both low pH and low alkalinity in your pool.
However, the pool pH fluctuates a lot when the alkalinity is out of range. The pH could be high or low. It changes randomly as long as the alkalinity is not in the required range.
Should I raise pH or alkalinity first?
If the alkalinity and pH of your pool are both low, then it is better to raise the alkalinity first before the pH.
Raising the pH when the alkalinity is still low is a tedious task to handle. For a new user, it could be almost impossible because the pH of the water is never stable in such conditions.
It could be low now and high for a couple of minutes. So, adjusting the pH is very difficult. But if the alkalinity is adjusted first, the pH can easily be corrected. Sometimes it corrects itself on its own.
How do you raise the pH and alkalinity at the same time?
As we started earlier in the article, we are more concerned about using baking soda and soda ash because we notice that a lot of pool owners prefer them, perhaps because they are natural compounds and are a bit less expensive.
To raise alkalinity and pH at the same time, you need to know the level of both parameters.
- If the alkalinity is far below 80 ppm and the pH is not too far from 7.2, you may just need to use only baking soda.
- If the alkalinity is not too far from 80 ppm but the pH is far below 7.2, you may need only soda ash.
- But if both variables are very low, you may need to use both baking soda and soda ash.
However, follow the instructions on the product packaging to know the right amount to add. For this reason, you need to purchase them from the pool store.
Also, remember that you need to balance the alkalinity first before the pH. So, follow the instructions below to learn how to balance alkalinity.
To add baking soda to a pool,
Check your pool’s alkalinity: Knowing your pool’s total alkalinity level can help you determine the amount of baking soda to add. But, first of all, you must be sure that the alkalinity is low.
Purchase a sufficient amount of baking soda: If your pool’s alkalinity is significantly low, a five-pound container of baking soda will most likely not suffice. It would be preferable if you had more. You should check with your pool supplier or the merchant to see how much you can buy and what the most gigantic container size is.
Know how much to add: If your pool’s alkaline level is too low, the water will become acidic. The trick is to know how much baking soda to add to the pool. You can start by adding half or three-quarters of the amount recommended. If your pool’s alkalinity remains low after adding this amount, you can add extra baking soda.
Dilute the baking soda: Instructions for diluting sodium bicarbonate are included with each container. Don’t forget to dilute your mixture.
Pour it in the pool: Baking soda is a water-soluble powder that dissolves fast. To boost alkalinity, add the recommended amount to the pool. Avoid pouring everything into one spot, and don’t do it where there’s a lot of wind, because the powder particles could get into your eyes and mouth.
Retest after some time: After applying all of the baking soda to your pool, you can retest to see what the results are after six hours. Even if you are unable to recheck within six hours, you should not wait longer than 24 hours.
Test for pH as well: It should probably be within the recommended range. If not, you would need to aerate the water or add a small amount of soda ash to correct the levels.
To add baking soda, repeat the above process but with soda ash instead of baking soda. Remember, you only need to add a small quantity, so it doesn’t have a significant effect on the alkalinity. Better still, aerate the water so it doesn’t significantly affect the alkalinity.
Does raising pool alkalinity raise pH?
Yes, when you try to raise the alkalinity of your pool water, the process also affects the pH values. However, the effect is not much, but if you add a large amount of baking soda or other alkalinity increaser, it can have a significant effect on the pH.
Can you raise pH without raising alkalinity?
It is almost impossible to raise pH without raising alkalinity with soda ash or some pH reducers. However, the effect on alkalinity is usually insignificant.
You can also raise pH without raising alkalinity through aeration. That is a process known as degassing. In the process, some amount of acids is removed from the pool as gas. This helps the pH of the pool water rise without any significant impact on the alkalinity.
How much baking soda does it take to increase alkalinity?
We have stated this before; to raise the pH of 10,000 gallons of pool water from 7.2 to 7.6, you need to add about 21 lbs of baking soda. But adding such an amount would raise the total alkalinity to about 150 ppm. That is too high for a pool.
But if you are using soda ash, you only need about 12.2 ounces to raise the pH of 10,000 gallons of pool water from 7.2 to 7.6. However, such an amount will only add about 10ppm to the overall alkalinity.
Is baking soda the same as soda ash?
No, baking soda is not the same thing as soda ash. Soda ash is sodium carbonate (Na2CO3) with a pH range of 10.9-11.6, while baking soda is sodium bicarbonate (NaHCO3) with a pH of about 8.3.
Is baking soda the same as alkalinity increaser?
Baking soda is an alkalinity increaser. However, there are other alkalinity increasers that are produced mostly with baking soda. Nevertheless, not all alkalinity increasers are made with baking soda.
If you are using any alkalinity increaser for your pool, we recommend using the ones made with baking soda.
So, baking soda can be said to be an alkalinity increaser, but not all alkalinity increasers are baking soda.
How long after adding baking soda to the pool can you swim?
Unlike pool chlorine, where you need to wait for about 4 to 6 hours after adding it, you can start swimming immediately after mixing the baking soda in your pool.
However, make sure that the sodium bicarbonate has dissolved completely and that the pool alkalinity is within the recommended range of 80-120 ppm.
So, we always advise waiting for about 2 hours after testing to allow the compound to circulate for at least one full cycle.
