Have you wondered about that itchy feeling in the eyes and face or skin rashes? Yeah! It often happens if you are a regular swimmer. All these issues are caused due to an imbalance in both the pH and alkalinity of the water.
Most often, the increased level of alkalinity in the pool leads to physical problems in the swimmers. The alkalinity of a swimming pool is the total concentration of alkaline substances present in the pool.
Maintain the accurate alkalinity of 80-120 ppm (parts per million), which a liquid drop testing kit can measure.
There are three conditions of alkalinity- high, low, and accurate.
High alkalinity is the high content of alkaline substances dissolved in the pool water. On the contrary, low alkalinity means a lower proportion of the same. At the same time, an accurate level is ideal with the right amount in place.
High alkalinity can prove to be hazardous to one’s health. Therefore, lowering pool alkalinity may prevent any potential harm.
Pool owners use various modern-day methods and techniques for lowering pool alkalinity. Alkalinity and pH of the pool are both interrelated terms. It is impossible to reduce one without affecting the other.
The pool’s pH is also reduced to lower alkalinity, which can later be extended to the optimum level.
A liquid drop testing kit can be used to measure the pool’s alkalinity level. It provides more precise results than any other instrument, like strips. Adding acid will surely decrease the alkalinity of the swimming pool.
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Table of Contents
Most Pool Owners Involve the Following Method to Reduce the Alkalinity of Water
Adding Muriatic Acid
This acid comes with instructions for measuring the concentration that needs to be added. One could calculate it online or using digital calculators according to their preferences.
Add the resultant amount of muriatic acid and supply a proper amount to the pool’s deep end. It then must be facilitated by the pool pump for mixing deep down.
Now, recheck the alkalinity. If it is above 80-120 ppm (parts per million), add acid again until it reaches the required level. Leave the pool undisturbed for 24 hours when the necessary proportion is accomplished.
Once alkalinity has been balanced, the pool should be isolated to increase the pH level through aeration, which involves exposing the pool water to air. It takes 48 hours to do so.
It is essential to maintain the optimum level of alkalinity because the increase in alkalinity causes an imbalance in the level of calcium in pool water which leads to problems of redness of eyes, dry skin, irritation in eyes, itching face, scalp, ear aches in swimmers.
Apart from physical problems, high alkalinity is also known to cause complications like cloudiness of water, circulation problems, damage to filters, algae, and calcium accumulation in the pool.
Quantitative Specifications
Hydrochloric acid (HCl), also known as muriatic acid, is the aqua solution of hydrogen chloride. It is colorless and has a pungent smell. It is a strong acid and is capable of even corroding metals.
Muriatic acid is used for lowering pool alkalinity. The amount to be added first needs to be calculated by the defined formulae to avoid mistakes.
One gallon of muriatic acid reduces the alkalinity of the pool by 50 ppm (parts per million). For example, if the reading of alkalinity of the pool is 100 ppm and one gallon of muriatic acid is added. The alkalinity of the pool will be reduced to 50 ppm.
Usually, two cups of muriatic acid are safe to add in 24 hours. However, factors like the pool’s size, water volume, and the acid’s strength determine the amount of acid to be added.
In 5000-10000 gallons of the pool, 1 cup would be safe. Likewise, the amount of muriatic acid is added. The acid is not directly added to the pool water or can cause heart, respiratory, skin, and lung problems in swimmers.
Therefore, always add muriatic acid to a bucket of water to dissolve it by vigorous stirring. While diluting muriatic acid, always add the acid to the water instead of adding the water to the acid to avoid acid splashing. It can cause inflammation, burns, and injury.
Then add the mixture to the pool at the deep end, and don’t let the pool’s pH fall below 7.4. Let the pool undisturbed for 24 hours allowing it to mix evenly in the water.
While handling muriatic acid, always remember to carefully read the safety instructions, as hydrochloric acid can lead to apoptosis and necrosis of cells and burns. So, always wear gloves, shoes, and proper clothing, avoid taking in fumes and open it only while using and close it immediately.
Aeration process: Aeration increases the pH of the water. It is done with:
- Bubblers
- Fountain
- Downward jet flowing
- Water splashing
When the alkalinity of the water is low, the pH of the water is also decreased. This means the acidity of water is increased, and increased acidity is more carbon dioxide.
With the aeration process, carbon dioxide is released from the pool. So, the reduction in acidity will cause the pH to increase.
Bubblers are used for the formation of bubbles. In this, an increase in pH depends on the size and quantity of the bubbles. The large size of bubbles rapidly increases the pH of water.
The swimmers or other employed people can do the splashing. Splashing is more suitable than other methods. In this, water is continuously splashed with hands and legs.
The pH increases instantly when the alkalinity of the pool is high. If the aeration process is robust, the outcomes usually take more time, and its effects last longer,
The less effective process will show its results in a short duration and will only be there for a while.
Addition of Dry Acid
Dry acid is Sodium Bisulfate. It is a granular acid and is highly soluble in water. This makes it desirable to lower the alkalinity of the pool. However, it is less common because of its costly nature and rare availability.
Being a weak acid, it requires less care while handling than muriatic acid.
Special precautions need to be taken while preserving it. Store it in a cool and dry place to prevent it from being contaminated due to moisture.
For adding dry acid to the pool, initially, one is expected to read the instructions given in the bottle or instruction manual to prevent mishaps.
Measure the alkalinity of the pool by using strips or a testing kit. Accordingly, a digital calculator calculates the amount of dry acid needed to decrease the alkalinity to the required level.
As it is a granular acid, it must be dissolved in a bucket filled with three-quarters of water employing a wooden stirrer. Otherwise, lumps of acid will settle in the pool and will destroy the swimming pool. Then add the mixture at the deep endpoint and border of the pool for adequate mixing.
7.4-7.5 pH of pool and chlorine content of 3 parts per million is considered safe for swimming.
But the pH above 12.5 and alkalinity above 120 parts per million of a pool is termed an alkaline pool. The high alkalinity of the pool can lead to problems ranging from cloudiness in the pool to skin, eyes, ear issues while swimming, and an unstable pH.
It is safe to swim in a pool even in high alkalinity only if chlorine and pH are maintained and cautions like goggles and earplugs are used while swimming to prevent the direct contact of eyes with water and limit your time in the pool.
High alkalinity also increases the calcium levels in the pool, making it a breeding ground for bacteria, parasites, fungi, and algae that are dangerous and could be fatal if persisted for a longer duration.
This will cause diseases and the spreading of infections. Along with this, it will also cause damage to pool walls and will reduce the longevity of the pool.
Pool owners are required to check the alkalinity of the pool regularly and maintain it accordingly to avoid such issues and maintain hygienic and assured conditions inside and around the swimming pool.
Causes of High Alkalinity in the Pool
Numerous factors cause high alkalinity. Some causes can be easily detected, while others are difficult to distinguish and gradually degrade the swimming pool.
High alkalinity is the presence of carbonates and bicarbonate in the pool water, which are very difficult to eliminate. Major causes of high alkalinity are:
Adding Soda Ash to Raise pH
Soda ash is Sodium Carbonate. It is used to increase the pH of the pool. When 2 oz of sodium carbonate is added to the pool to raise its pH, it increases the pH by 0.2.
And as pH is closely related to the alkalinity of the pool, an increase in pH will also lead to an increase in alkalinity. Thus, alkalinity is increased by seven ppm.
Adding Hypochlorite Chlorine
Hypochlorite Chlorine is rarely found in the pool, even if it is found in small amounts.
It produces hydroxide as the byproduct when released into the pools. It is due to the frequent usage of sodium hypochlorite chlorine or calcium hypochlorite chlorine. As a result, produced hydroxide increases the alkalinity of the pool.
Inaccurate Testing Methods
As we are aware of the methods used for testing the pH and alkalinity of the pool, liquid drop testing kits and strips are primarily used.
A liquid drop testing kit gives more accurate results than strips. The testing kit involves reagents that give color by the chemical reactions and tell the pH and alkalinity of the pool.
Using strips can lead to inaccurate measurement of the level of alkalinity, which will lead to the addition of the incorrect amount of chemicals for the wrongly recorded increased or decreased level of alkalinity and pH.
Using a testing kit for better results and maintaining a good pool is always best.
Pool Plaster
Reconstruction or renovation of the pool is done with plaster.
Proper time should be given for drying the plaster; otherwise, half-dried plaster will mix with the pool water and produce Calcium Hydroxide in the pool. Calcium hydroxide increases the alkalinity of the pool.
Adding Borax
Borax is used in case the pool’s water is highly acidic to increase the pH of the water. Borax produces borates in the water. It increases the alkalinity of the pool.
It also affects the health of the swimmers by causing organ damage, cell injury, reproductive problems in both males and females, and other health-related issues.
Adding Alkaline Water
Swimming pools require regular filling of the water. If the water coming from the source is alkaline, it increases the pool’s total alkalinity up to a certain level.
Therefore, the water source must be checked regularly for its alkalinity before filling the swimming pools. In this case, when total alkalinity is very high, it becomes challenging to bring it back to the accurate level.
High Water pH
If due, for any reason, the pH of the water is increased, Carbonic Acid, which is dissolved carbon dioxide, is converted into bicarbonates in an alkaline medium.
The bicarbonate mixes with the pool water and increases the alkalinity of the pool.
Wrapping Up
Maintaining a balance in the pool water is essential. A higher or lower alkalinity may cause many unavoidable problems. The high alkalinity of the pool is a significant problem and less common than low alkalinity.
Lowering pool alkalinity must be done with proper measures and precautions.
The pool owner must close check on the pool alkalinity and maintain an ideal level that ranges between 80- 120 ppm (parts per million).
