A Guide to Using Algaecide in Your Pool

Algaecide is an excellent tool that pool owners commonly use to kill off algae in pool water. While it shouldn’t be used as a replacement for chlorine, algaecide is an effective option if you need that extra power to kill off an algae infestation. Whether you are a new pool owner or simply want to brush up on your algaecide knowledge, understanding how to use it will ensure you use it as effectively as possible.

In this article, I provide a full breakdown of what algaecide is, list the different types, and explain how to utilize it effectively.

Main Takeaways

  • Algaecide has a copper base that attacks algae and stunts their growth.
  • There are different types of algaecide: quat pool algaecide, metallic pool algaecide, polymer pool algaecide, and sodium bromide.
  • While algaecide is formulated specifically to get rid of algae in a pool, chlorine is still the most effective solution to killing algae.
  • You should add algaecide to your pool every week as a secondary sanitization option.

What is Algaecide, and How Does It Work?

Algaecide is not a quick solution to get rid of algae entirely in your pool. It is more often used as a preventative measure rather than a reactive treatment. These chemical compounds contain components that both kill algae but also stunt their growth in your pool.

Most of the algaecides on the market contain a copper base, usually derived from copper sulfate. These chemical compounds utilize metal as its primary atom, which helps attack algae much more effectively. Algaecides’ main job is to discourage the typical cellular growth process of algae. Though blocking cell division or energy transfer, they limit the creation of newer cell proteins, which help algae survive.

It is important to note that all pesticides, including algaecides, must be implemented following the product label registered with the EPA (Environmental Protection Agency). When you use algaecides, please ensure that you are wearing the appropriate personal protective equipment, which will be recommended on the product label.

Different Types of Pool Algaecide

Your investment in an effective pool algaecide is a crucial decision. You can choose from a few different types of algaecides, each with its own use cases. Below, I laid out the best pool algaecides on the market in each type and when to use them. Each of these products can kill all sizes of algae, isolated blooms, and in different stages of the algae growth.

Quat Pool Algaecides

A Quat pool algaecide, also known as a Quaternary Ammonium compound, is utilized as microbial disinfectants. They are positively charged and attach themselves to algae cells that are negative. Once they are bonded with the algae, they disintegrate the exterior protective membrane.

This penetration enables the chlorine to kill the cell’s nucleus ultimately. If you want the most bang for your buck, this is an excellent algaecide option that comes in both 50% and 10% concentrations. You can pick some up from Clorox for pretty cheap.

Clorox Pool&Spa Green Algae Eliminator2

Here's a Clorox algaecide that works well in every pool I've used it in.

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Metallic Pool Algaecides

This type of pool algaecide holds Copper ions, a trusted solution in water treatment for thousands of years. To minimize potential staining from overuse, the copper gets attached to amino acids. Much like the other algaecides on the list, the positively charged metal ions fix themselves to the algae, invade the algae walls, poison the enzymes, and attack the nucleus.

Metallic pool algaecides are an ideal option for black algae and are also useful against algae blooms. Most average copper algaecides run between 7% and 9% copper strength or concentration. And according to studies, copper-based algaecides are proven to be the most effective in killing cyanobacteria because of how they attack the membrane. Below is a good option from In the Swim.

In The Swim Super Pool Algaecide

In The Swim makes great pool maintenance products, and this algaecide works very well if you need a metallic pool algaecide.

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Polymer Pool Algaecides

Polymer pool algaecides are Poly-Quat compounds with longer chains of carbon. These are versatile algaecide options because they are both non-staining and non-foaming. These negatively charged polymers spread over the algae cell’s surface much more quickly and surround the cell for the kill.

Poly-Quats are much longer-lasting and more effective than regular Quat algaecides but are also costly. These algaecides usually get sold in 60% and 30% strengths or concentrations. If you are someone on a budget, you may want to research other options. But this multi-season algaecide provides a consistent cleaning no matter what time of year it is. Rx Clear makes a good solution here.

Rx Clear Algaecide 60 Plus

Rx Clear makes a strong Poly-Quat algaecide that is more expensive, but also more effective.

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Sodium Bromide

Sodium Bromide is not an algaecide, but its mixture with granular chlorine makes for a perfect catalyst to rid your algae-filled pool. The pool shock plays a pivotal role in converting the various bromides into a capable algae eliminator.

Bromides are not usually used to prevent or control algae, but it gets used in the more severe cases of algae growth in the pool. It also works effectively with yellow or green algae that are not adequately responding to chlorine by themselves. No Mor Problems makes a good option.

United Chemical No Mor Problems Swimming Pool Algaecide

United Chemical makes an effective sodium bromide option for tough algae outbreaks. It's also used to prevent algae.

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Different Types of Algae

Algae can come in many different forms. Below are the main types of algae that will make a home in your swimming pool:

  • Green algae – also known as blue-green algae, is the most popular type, and it needs sunlight, warmth, and water to survive.
  • Black algae – a strain of blue-green algae that is attracted to plaster pools and contains a thicker cap that offers extra protection against algaecides.
  • Yellow algae – this is a different variation of green algae, which is chlorine resistant and can still live without the help of sunlight.
  • Red algae – these algae are associated with a different bacteria genus and can survive without sunlight.

Why Chlorine is the Best Weapon Against Algae

Although algaecide is specifically designed to kill algaecide, it is not necessarily the most effective solution. Chlorine is much more successful at getting the job done, even if your walls are extra slimy and your walls are cloudy. According to the Missouri Department of Health, chlorine provides a cost-effective solution that reacts with water to produce a sanitizing species, hypochlorous acid, to kill algae.

Chlorine’s differentiating factor is its ability to oxidize single-celled algae and bacteria. When chlorine gets implemented, it trades electrons with the algae. When this exchange happens, the cell walls of the algae get ruptured. As soon as the process is complete, the algae cells are deprived of the necessary nutrients. Over time, consistent use of chlorine will limit the algae replication and growth process.

Much of the battle here is ensuring you maintain an ideal pool water chemistry with chlorine, bromine, or biguanide. Combined with a balanced pH level, this will be an effective protector against algae growth in your pool.

When to Use Algaecide

If you do not use chlorine to kill algae in the pool, you should aim to add algaecide to your pool on a weekly frequency. Algaecides serve as a secondary sanitization option for your maintenance system and prevent the ugly sight of algae in the pool.

You want to try and be on the proactive side of algae growth and implement algaecide consistently. It is also smart for you to perform algaecide after each shock treatment session. If you’re trying to clear a green pool with shock and algaecide and both don’t seem to be working, check out my article on what to do next when shock and algaecide aren’t enough.

Algaecide can also be a good treatment for pool foam.

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Final Tips on Using Pool Algaecides

As you can see, many components go into effectively implementing pool algaecides. Now that you know the different kinds of products and the proper process, you must ensure that you are doing the small things correctly.

Before doing anything with an algaecide, always read through the label for specific dosages and tips. It is also essential for you to avoid mixing pool shock and algaecide simultaneously. Ideally, wait until chlorine levels decrease below 5 ppm before pouring in the algaecide. Once you have dumped the algaecide into the water, you can also turn on the filter so you can spread the solution.

The pH balance of the pool should also be somewhere near the middle. It would help if you avoided higher pH, calcium hardness levels, or alkalinity. Another way to ensure the best performance from your algaecide is to clean the pool beforehand. Debris, leaves, and other particles tend to consume algaecide, which limits it from doing its job.

The best thing you can do is to take your time and invest in a solution that best addresses your individual needs and situation. By following the process with focus, your swimming pool will be well on its way to becoming fully clean again!

Questions? Feel free to shoot me a message, and I’ll be glad to help.

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