What Causes Low Alkalinity In A Pool?

There are a variety of reasons for your pool’s low alkalinity level, and you’ll need to investigate each one to figure out what’s causing it and how to fix it.

It’s conceivable that there are too many impurities in your pool water if the alkalinity level is low. It’s very natural for your pool’s alkalinity to diminish throughout the season.

The majority of the time, this is due to natural factors like the evaporation of water agitation. ‘Water degassing’ is the process of releasing dissolved carbon dioxide from your pool during the hot summer months.

This has a direct effect on total alkalinity, lowering it below the normal level. Excessive use of alkalinity-lowering chemicals, as well as the use of too many chlorine tablets with a low pH, and other factors listed below could be responsible for the alkalinity drop in your pool.

The following factors could be contributing to your pool’s low alkalinity level.

  • You might want to lower your pool’s alkalinity level and add way too much alkalinity reducer. This might cause your pool’s alkalinity level to drop below normal, making it unsafe to swim in.
  • You may have also backwash your pool and drained a substantial portion of the water during its regular maintenance period. When you add fresh water to your pool without first stabilizing the alkalinity level, you risk lowering the pool’s total alkalinity.
  • Another reason for this is when your pool has come into contact with a nearby source of water, such as rain, floods, or melted snow. Remember that the local source of water is already low in alkalinity, and when it mixes with your pool, it lowers the alkalinity level even more. Any water source with a low alkalinity level can lower the alkalinity level of your pool.

Why is it necessary to raise your pool’s alkalinity level?

If your swimming pool contains low-alkalinity water, it can cause irreversible damage. You run the risk of having your pool walls etched, delaminated, or fractured.

Under the corrosive water, some metal surfaces will give way and melt, resulting in a discolored pool wall. Even little changes in the chemical makeup of pool water can induce significant pH swings.

The phenomenon of pH bounce occurs when the pH level becomes uneven, and it might result in low alkalinity in the pool, depending on the circumstances.

The typical amount of chlorine added to your pool would be ineffective if your pool’s alkalinity was low. Only when more than the normal amount is added for standard outcomes would it be advantageous.

This implies you’ll have to buy more chlorine and spend more time trying to acquire the right concentration of the material.

Aside from the impacts on your pool, a low alkalinity swimming pool is dangerous for swimmers since the acidic water can irritate their noses, eyes, and skin.

Is it safe to swim in a pool with low alkalinity?

Swimming in a pool with low alkalinity levels is not recommended due to the possibility for swimmers to have side effects such as eye, nose, and skin irritations.

Apart from hurting the skin, low alkalinity can damage the pool’s surface and interiors, making it difficult to maintain a consistent amount of chlorine in the pool.

A decrease in the amount of chlorine and calcium hardness in your pool causes these adverse effects.

The water becomes corrosive as the chlorine and calcium hardness levels drop, causing damage to the pool’s surface and equipment, as well as eating away at the pool’s walls and floors.

Why is balanced alkalinity important?

Alkalinity serves as a pH buffer. When alkalinity is balanced, it helps to prevent pH variations that are too abrupt. Low alkalinity readings increase pH sensitivity, which means your pH might quickly go from high to low and back.

A low alkalinity level can cause damage to your pool’s surface, tile grout, and equipment, as well as itching skin and burning eyes.

High alkalinity, on the other hand, might limit pH sensitivity, causing your pH to stay high and reducing chlorine efficacy.

If your chlorine isn’t being used to its full potential, a high alkalinity rating might cause your pool to become hazy or even green. High alkalinity, like low alkalinity, can cause burning eyes and itchy skin.

How to raise pool alkalinity

It should come as no surprise that adding an alkalinity increaser to your pool water will increase total alkalinity. Three substances can be used to boost total alkalinity.

Your choice of chemical is determined by your cyanuric acid and pH levels. It’s better to add a stabilizer if your cyanuric acid levels are similarly low.

This will raise your total alkalinity as well as your cyanuric acid levels. It is preferable to add soda ash if your pH levels are low.

Both pH and total alkalinity will rise as a result of this. It’s better to add sodium bicarbonate to enhance total alkalinity if your pH and cyanuric acid levels are within the suggested values.

Sodium bicarbonate is the most effective approach to increase total alkalinity while reducing pH and cyanuric acid levels.

How to add alkalinity increaser to a pool

Sodium bicarbonate (also known as sodium hydrogen carbonate) is an alkalinity increaser that helps to maintain a stable pH. It improves overall chlorine efficiency while stabilizing pH variations and protecting pool surfaces and equipment from corrosion.

Alkalinity increasers are necessary if alkalinity levels are low and pH readings vary throughout the day, as well as for daily pool maintenance to assist reduce the need for additional pool chemicals.

To add alkalinity increaser to a pool,

  • Check your pool’s overall alkalinity: Knowing your pool’s total alkalinity level can help you determine whether you need to increase or decrease it. If your pool alkalinity is less than 80 ppm after testing, it’s time to increase the pH concentration.
  • Purchase a sufficient amount of alkalinity increaser: If your pool’s alkalinity is significantly low, a five-pound container of alkalinity increaser 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. Is it too high? There are just as many issues. The trick is to know how much alkalinity increaser to put in your low-alkalinity pool. Half or three-quarters of the amount recommended should suffice. If your pool’s alkalinity remains low after adding this amount, you can add extra baking soda.
  • Dilute the alkalinity enhancer: Instructions for diluting sodium bicarbonate are included with each container. Don’t forget to dilute your mixture.
  • Pour it in the pool: Alkalinity Booster is a water-soluble powder that dissolves fast. To boost alkalinity, add a recommended amount to the pool. Avoid pouring everything in 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 alkalinity-increasing treatments 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.

Can you swim after adding an alkalinity increaser?

It’s fine to swim right after adding it, but for best results, you should let it dissolve properly. If you are in a hurry, turn on the circulation system in your pool to help it dissolve faster.

The majority of alkalinity increasers will dissolve in the water within an hour of being added, making swimming safe. So you should wait for at least an hour before diving it

Can I use baking soda to raise the alkalinity of my pool?

Sodium bicarbonate is the only active ingredient in some kinds of alkalinity increasers. So, how about it? Baking soda is made up of sodium bicarbonate.

Baking soda raises pool alkalinity levels and is often less expensive than Alkalinity Increaser. It is identical to the chemical used to boost water alkalinity, and it will offer you the same results as alkalinity powder.

Baking soda, on the other hand, is a much larger particle that, if used in large amounts, will cloud the water. It is normally safe to use if you need to significantly increase the alkalinity of your pool with one or two pounds of alkalinity powder.

If your water balance requires a major increase, however, a genuine alkalinity increaser is recommended, as it is a finer granule that will rarely cloud the water, even when applied in large quantities.

Is alkalinity increaser the same as pH increaser?

Sodium bicarbonate is an alkalinity increaser (also called sodium hydrogen carbonate). Alkalinity Increaser will not raise pH above its typical range when diluted in water.

pH is buffered by alkalinity, which helps to avoid pH oscillations. Sodium carbonate is a pH raiser (also called soda ash). The terms alkalinity and pH are not interchangeable.

Water alkalinity is a measure of the carbonate and bicarbonate levels in the water, whereas water pH measures the quantity of hydrogen (acid ions) in the water.

What is alkalinity increaser made of?

Sodium bicarbonate, which is a harmless chemical, is used in the vast majority of alkalinity increaser products.

Because sodium bicarbonate is inherently alkaline, with a pH of around 8, it is believed that when it is added to a pool, both alkalinity and pH will rise, enhancing clarity and stability.

How does pH affect your pool?

Before you start thinking about enhancing the alkalinity in your pool, you should first understand how pH affects the water. Keep in mind that alkalinity is not the same as alkalinity in pH.

An alkalinity is a group of compounds that help raise the pH of a pool’s water. A pH measurement in chemistry determines how acidic or basic water and water-based compounds are.

The optimal pH range for pool water is 7.4-7.6, indicating that it is neither too acidic nor too alkaline. The water becomes toxic in a variety of ways when pH levels fall too low or rise too high.

With high pH values, the calcium in your water will interact with the carbonates in the surrounding area, resulting in the formation of an unattractive scale along the pool’s edges.

You’ll also note that the water begins to fog, which causes people to cease swimming in the pool. Calcium carbonate will clog the pool filter, causing it to become less effective.

When pH levels go below 7.4, you’ll have to be concerned about the water becoming too acidic. If your pool’s walls and bottom are made of plaster and grout, these materials will begin to deteriorate.

Algae will eventually grow in the pool water, causing health problems. Any metal in your pool may corrode over time, resulting in staining.

Increasing or decreasing the amount of alkalinity in the pool, which is referred to as buffering, is a smart idea whether the pH levels in your pool are too low or too high. Baking soda is the most commonly used buffering agent.

What is the difference between chlorine and shock?

The active chemicals that sterilize your pool are comparable in granular chlorine, liquid chlorine, chlorine tablets, and granular shock. What makes shock different is the chemical’s potency and how it’s designed to be used.

You can’t shock your pool with standard 3-inch chlorine tablets, unfortunately. Chlorine sanitizing products are wonderful for keeping chlorine levels up, but they don’t always get rid of new trash, bacteria, or algae.

To kill germs and chloramines, an effective shock product should boost free chlorine levels above 5 parts per million for several hours. Keep in mind that if you have visible algae (black algae, mustard algae, or green algae), you may need to double or triple the normal pool shock dosing to get rid of the problem.

That’s when shock’s power comes into play. For example, some 1-pound bags of shock treatment can deliver 7 parts per million of free chlorine per 10,000 gallons of pool water.


Pool alkalinity is an important aspect of pool chemistry, and inadequate pool maintenance can cause drastic changes. A good swimming pool has a balanced alkalinity level, whereas a low alkalinity level spells doom for your pool and the swimmers.

Alkalinity can be managed through regular checks and tests, as well as the addition of alkalinity increasers, which were necessary to maintain balanced alkalinity in the pool. You will save money by not having to buy new pool equipment or chemicals.

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