How to Get Rid of Black Algae in a Swimming Pool

how to get rid of black algae

There are different types of algae that one can encounter in his or her pool.  The first type of algae is called black algae. Black algae are one of the most common types of algae. It is not harmful itself but it helps in producing different types of bacteria in the water that makes the water unhealthy to swim in for the swimmers. Therefore, it is necessary to get rid of black algae and in this article, some necessary measures to get rid of them are going to be discussed along with a brief discussion about them.

What Is Black Algae?

Single-celled organisms that grow in big colonies are known as black algae. These kinds of algae are less visible than other types. They are usually seen on the bottom of the pool where it is getting exposed to water. Black algae can also be present on the sides of your pool, in the corners, and in the middle. It is a type of algae that may grow when the water level in the pool gets too low. This is because black algae can attach themselves to any non-absorbent material, such as plastic. Unlike other algae, it has also chlorophyll but the green color of them is covered with some other compounds that make them look black.

What Causes Black Algae?

There may be a higher pH level than regular in the water of a pool that may cause black algae growth all over the pool and it may happen if the pool is not sanitized regularly. Besides, chlorine keeps the water of the pool clean from any kind of bacteria, fungus, algae, and so on. Therefore, when the water of the pool has a lower amount of chlorine, unlike other algae, black algae is also grown faster. Irregular circulation of the pool water causes the growth of this type of algae in the pool too. Moreover, not doing pool water filtration is another cause behind the growth of bacteria, fungus, algae, and so on including black algae in the pool water.

How to Get Rid of Black Algae?

Black algae are needed to be killed fast before it gets a growth themselves and produces bacteria in the pool water, making the water polluted and unhealthy to swim in for the swimmers. To get rid of black algae, an individual must take some necessary measures regularly. By taking these necessary measures, he or she can easily keep their pools clean and safe from the growth of black algae.

How to get rid of black algae some of the measures are discussed below

Testing Pool Levels

The first measure to get rid of black algae is testing pH levels, alkalinity levels, and other chemicals in the pool water regularly. One can test the pH level, alkalinity level, and other chemicals of the pool water weekly to measure whether the levels and amount in the pool water are satisfactory or not. This testing of pool water pH level, alkalinity level, and amount of chemicals can be done twice a week.

One must ensure that the pH level of their pool water is not less than 7.4 and not more than 7.6. Besides, the alkalinity level of the pool water is not less than 120 ppm and not more than 150 ppm. Moreover, other chemicals are present in an appropriate amount. If the levels of pH and alkalinity and the amount of the other chemicals are not present at a suitable proportion, there may be a risk of growing black algae and bacteria from black algae that will pollute the water of the pool and will require immediate action.

Sanitizing Pool Stuffs

Another measure to get rid of black algae in the pool is to sanitize all the kinds of stuff related to the pool. In a pool, there may be bathing suits, wiping down toys for the pool as well as various types of equipment that require washing and drying regularly. Therefore, regular cleaning of these kinds of stuff related to the pool with sanitizer helps in keeping them free from any kind of bacteria, fungus, or algae including black algae and so on. To sanitize these kinds of stuff regularly Clorox cleaner can be used. This sanitizer helps in killing any kind of stubborn algae including black algae.

Scrubbing Black Algae

Scrubbing the pool is the only way to get rid of black algae since it removes the algae’s protective coating, making it vulnerable to chlorine. One may have tried all the methods to remove black algae from the pool, but they all may fail. So he or she may think of a different solution. Not being an expert in this field and not knowing the best way to remove it from the pool, one may decide to use bleach while scrubbing. It is important to know the right tool to use to remove black algae from the pool. There are various ways that he or she can use to do it, but it is suggested that they should use the bleach method. First, they need to buy bleach. They can purchase it at a hardware store and also online.

Adding Algaecide

Essential ingredients for maintaining proper water chemistry are good water chemistry, an adequate pH level, a low salinity, and a good algaecide. However, adding an algaecide to the pool can seriously damage the pool, make it unsuitable for swimming, and have negative effects on the health of all aquatic life in your pool. There are many different types of algae and their growth patterns often vary.

Some types of algae will be very easy to control while others are much more difficult. One must choose what type of algae they want to try and which type they want to avoid. For example, if anyone is trying to control Kocheria dendritic, which is a type of green algae, they will need to use specific algaecide products and the black algae, are the other specific algaecide products.

Triple-Shocking and Scrubbing Again

This stage will take around a week to complete. In a nutshell, one will shock their pool to fast elevate the chlorine level, then brush away at the algae (you will then repeat these steps). One has to make sure that the pool is shocked at night and that filter is running 24 hours a day, 7 days a week until the algae are entirely gone.

An aggressive approach is required the first time one shocks their pool. For every 10,000 gallons of water, add 3 pounds of shock. After shocking the pool for the first time the next day, they have to scrub the pool three or four times more. They will scrub in the same manner for a few days and re-shock the pool after three days (this can be done at a normal level). After the second shock, they will scrub your pool for a few more days. Although they may not be able to see the black algae at this stage, its roots are most likely still hiding in the pool’s walls.


With the water temperatures at such high levels, black algae will always be an issue. It’s seldom too late to clear away any dead algae from the pool if one does some extra research and prepares the environment for the algae to die off. Black algae are something they want to completely remove from their pool. It’s something that they could get rid of in a few hours, but if it’s left for weeks on end, it can harm the pool. The best time to remove black algae is when the water is warm and one doesn’t need to vacuum it. One can also use high-pressure jets to get rid of any remaining algae. They have to vacuum pool water with a strong vacuum cleaner. This is how they can get rid of any remaining dead algae that are lingering in the pool.

Keeping Water Moving

Every year, many homeowners spend a lot of time and money to keep their swimming pools looking clean. Unfortunately, this is not one of the biggest targets when it comes to cleaning the pool. If they want to keep their pool clean, they need to make sure that it is always moving.  This is why they want to make sure that they always have a circulation pump in their pool. This will ensure that the algae can’t attach to the walls of the pool and grow.

There are tons of other things that one can do to prevent algae growth.  They can use a nutrient solution to grow algae and keep it at bay. They can also use chemicals in your pool to keep the algae in check. Besides, with so many chemicals in the water, they end up with some black mold, algae, and other food particles that can block the filter. If they want to keep the pool looking beautiful and clean, they have to first eliminate the debris. The best way to do this is to run their filter constantly. Moreover, they can use water conditioners to keep the pool water clean.



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