How Do You Know if Your Alkalinity Is Low?

Maintaining the chemistry balance in a swimming pool can be challenging, but it is one of the most important responsibilities for you as a pool owner. Monitoring your pool’s alkaline levels is crucial, as there will be times when you will need to know how to decrease alkalinity in a pool or increase it. 

Ultimately, if alkalinity is not kept within the recommended range, it can cause irritation to swimmers, damage to the pool equipment, and even make it difficult for pool chemicals to work as they should. 

How do you know if the alkalinity in your pool is low? In this article, we will explore what happens when alkalinity is too low and how to return it to its balanced levels.

Low Alkalinity in Pools

Alkalinity refers to the amount of alkaline substances, particularly bicarbonates, present in the water and it’s usually measured in parts per million (PPM). When it’s low, the pH level can fluctuate beyond the optimum levels of eighty to 120 PPM. Anything below eighty PPM is too low and this is when problems can occur.

Common issues causes by low alkaline levels include:

Burning or Itching Eyes

Low alkalinity levels can cause the pH balance in the water to fluctuate, leading to irritation to the eyes and skin of swimmers.


When the alkalinity level is low, it can lead to corrosion of pool equipment, resulting in the formation of stains and discoloration on the pool’s surface.

Cloudy Water

A low alkalinity level can cause the water in the pool to become opaque, which will make it lose its attractive glow and make it appear contaminated or dirty.

Algae and Bacteria

Low alkalinity creates a comfortable breeding ground for unwanted algae and bacteria to grow. If left untreated, these growths can spread and attract insects and other unwanted pests.

How to Identify and Restore Low Alkalinity

If any of the above symptoms are present, it is highly likely you have low alkalinity. The easiest way to check is to purchase a test kit from your local pool supply store or online. These kits will give an accurate reading of your pool’s alkalinity level. If your alkalinity is lower than eighty PPM, consider some of the following treatments to get your alkalinity levels back where they need to be:

Alkalinity Increaser

An alkalinity-increasing solution is a good choice for regular pool owners because they are simple to use and will increase the pool’s alkalinity levels over time. These products are available in any pool store and require very little preparation before use.

Sodium Bicarbonate 

Sodium bicarbonate is a common household item: baking soda. This compound will help raise the pH and alkalinity levels. The amount of sodium bicarbonate required will vary depending on the size and type of pool you have. The industry standard is to add 1.4 pounds of baking soda per 10,000 gallons of water to increase it by ten PPM.


You may wonder, “how can I lower my alkalinity without chemicals?” This is one method. You can balance your pool’s alkaline levels by aerating the water using spray jets or fountain functionalities in the pool. It isn’t typically advisable for larger pools, as it requires a great deal of time and energy to raise pH levels.

Replace the Water

When low alkalinity has been overlooked or ignored and has got to severely low levels, the only option remaining could be to completely refill the pool with fresh water. 

Make a Splash With Pool Care Guy

Low alkalinity is a common issue, and can occur through poor maintenance but it can also come unexpectedly. If it does occur, it’s essential it’s dealt with in a timely and effective way. Don’t hesitate to get in contact with Pool Care Guy if you need assistance with any facets of your pool management!

Scroll to Top
Scroll to Top