5 Best Pool Algaecides – Easy Problem Solution

Last updatedLast updated: September 25, 2021
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Algae are an issue that most pool or spa owners are faced with at one point or another. Because algae can develop at a fast speed, they can ruin the water in your pool in just a couple of days. It is thus essential to use the best pool algaecide to get rid of these plant-like organisms and continue to enjoy your pool.

Finding the best algaecide for the pool is not very easy because there are lots of factors to take into account. We reviewed 32 of the best pool algaecides on the market and concluded that the PoolRx Pool Unit #101066 is the top solution against algae out there. This continuous algae eliminator fights against algae effectively and forms a steady residual that lasts for up to six months. We also included four more other quality algaecide in our top so you can easily find a model that best suits your needs.

When reviewing the best pool algaecide on the market, we looked at lots of features to determine which models should make it to the top. Some of the most important features we considered include the type of algae they can tackle, as well as the lasting period and capacity. We spent days reading reviews from professionals and consumers who tested the algaecide in their homes, and we summed up the results of our research in the comparison table below. To learn more about the algaecide we included, read the in-depth reviews, and if you want to find out more about how to find the best model for your pool, have a look at the buying guide at the end that has all the details you need to make an informed choice.

Top 5 Pool Algaecides Review 2021


PoolRx Pool Unit #101066Editor’s Choice

  • Type of algae: all types
  • Lasting period: 6 months
  • Capacity: 13.1 oz

More features: ideal to use with chlorine, salt, UV or ozone systems

After we reviewed dozens of pool algaecide, we concluded that the PoolRx Pool Unit #101066 is the best choice out there for the majority of users, and this is why we featured it as our editor’s choice. This algae eliminator can be used with a variety of systems, including chlorine, salt, UV, and ozone, and has a capacity of 13.1 oz. With a lasting period of six months, the PoolRx Pool Unit #101066 makes pool maintenance hassle free, as you don’t have to remember to replace it more often than twice a year.

The PoolRx Pool Unit #101066 contains a proprietary blend of minerals as well as a specially treated alloy cylinder that work together so the low levels of chlorine can be more effective in water. The chlorine lasts for longer because the minerals in the pool or spa are replenished as they come through the cylinder. The PoolRx Pool Unit #101066 algae eliminator is suitable for use with all types of algae and works in pools of up to 20,000 gallons. Rechargers are available for those who want to use this algae eliminator in bigger pools.

What stands out?

  • Easy to use
  • Long lasting
  • Works with all types of algae

What cons did we manage to find?

  • Expensive

Kem-Tek KTK-50-0006Best Value

  • Type of algae: green
  • Lasting period: not specified
  • Capacity: 1 qt

More features: non-foaming, compatible with salt systems, suitable for pools and SPA

Suitable for green algae, the Kem-Tek KTK-50-0006 is a 60% concentrate algaecide that can remove just about any type of algae from spas and pools and it also prevents re-occurrence after use. The non-foaming formula is safe for use in all types of pools and doesn’t cause any kind of damage at all. The high concentration offers better clarity for the pool, and the product is compatible with salt systems as well.

Because it doesn’t disperse in water immediately after use, the Kem-Tek KTK-50-0006 lasts longer than many of the other products we reviewed. However, you should also note that you shouldn’t use the pool the same day you used this algaecide. Besides doing a great job at eliminating algae and preventing them from reoccurring, Kem-Tek KTK-50-0006 also kills other organisms in water, thus leaving your pool free of any kind of contamination. Reviewers who tested this product mentioned that it works as expected in the majority of cases, and that it can be safely used on above ground pools. The Kem-Tek KTK-50-0006 comes in 1 qt bottles and you can use it in all types of pools and spa, including salt-water ones.

What makes it stand out?

  • Long-lasting effect
  • Safe for use in all types of pools
  • Non-foaming formula

Which disadvantages must you keep in mind?

  • You can't use the pool immediately after using this product

SeaKlearBudget Pick

  • Type of algae: blue-green, green, yellow, black
  • Lasting period: 90-days
  • Capacity: 1 qt

More features: non-foaming, non-staining, compatible with salt systems

Our budget pick, the SeaKlear algaecide, is efficient against multiple types of algae, including blue-green, green, black and yellow algae. With a lasting period of 90 days, SeaKlear leaves the water in your pool crystal-clear thanks to its non-foaming and non-staining formula. The product is compatible with saltwater, so you can safely use it in just about any type of pool. Besides killing most types of algae, SeaKlear also does a good job at preventing them from reoccurring, so you can enjoy clear water for longer.

With a formula that contains 11.8% copper sulfate pentahydrate, SeaKlear comes in 1 qt bottles that are recommended for pools of up to 10,000 gallons. According to the manufacturer, two bottles may be required to get rid of severe algae growth. Many of the consumers who tested and reviewed SeaKlear reported that the product does its job as expected. However, some of them mentioned that the actual lasting period is less than the 90 days listed by the manufacturer. SeaKlear is one of the best choices we have reviewed when it comes to the elimination of mustard algae. Keep in mind that you cannot use the pool the day you use this treatment to clear the water.

What stands out?

  • Efficient against most types of algae
  • Non foaming formula
  • Can be used in saltwater

What cons did we manage to find?

  • Not very long-lasting

Pool Mate 1-2150-02Best Set

  • Type of algae: green, black, yellow, pink
  • Lasting period: 2 or 3 oz per 10,000 gallons/ week
  • Capacity: 1 qt x 2

More features: non-metallic, for all pool types

If you’re looking for a non-metallic algaecide that can tackle most types of algae, the Pool Mate 1-2150-02 is an excellent solution. It can eradicate green, yellow, black and pink algae and is compatible with the vast majority of pools. The product is only available in two 1 qt bottles and is very easy to use even if you haven’t used an algaecide product before. In terms of how much to use, 2 or 3 oz per 10,000 gallons/ week is enough for effective results.

Users who tested the Pool Mate 1-2150-02 mentioned that this product provides great results in vinyl pools, but also in those made of concrete, gunite, or fiberglass. Unlike many of the other algaecide products on the market, this one only requires you to wait for up to 15 minutes before using the pool. The Pool Mate 1-2150-02 kills the algae, and you need to remove them from the pool by cleaning after 24 hours.

Why did it make our list?

  • Suitable for all algae types
  • Works in all kinds of pools
  • Non-metallic formula

What is not ideal about it?

  • Not available as a single bottle

hth Pool Algaecide Ultimate Algae GuardBest for Green Algae

  • Type of algae: green, yellow
  • Lasting period: up to 90 days
  • Capacity: 1 qt

More features: 6-in-1 product, non-foaming, compatible with salt systems, copper-free, swim immediately

A six-in-one product that eliminates algae from pools and spas and also does an excellent job at preventing them from reoccurring, hth Pool Algaecide Ultimate Algae Guard is the best solution we found against green algae. While it also works on combating yellow algae as well, this algaecide truly shines against the green type. This product has a non-foaming formula and is compatible with saltwater, so you can use it in most pools.

Something that we liked when reviewing the hth Pool Algaecide Ultimate Algae Guard is the fact that you can swim immediately after using it in water, which is not something you can do with all of the products available on the market. According to many reviewers, this algaecide is very easy to apply and is highly efficient in both pools and spas. It is available in 1 qt bottles and the lasting period indicated by the manufacturer is up to 90 days. The hth Pool Algaecide Ultimate Algae Guard helps protect the water in your pool and spa from future algae blooms.

What makes it special?

  • 6-in 1 functionality
  • Non foaming
  • You can use the pool immediately

What cons did we find?

  • Only works on green and yellow algae

Things to Consider

Pool algaecides are the most effective and easy way to get rid of the algae that made your pool their home. Choosing the correct type of algaecide to use in the pool may seem like a daunting process, particularly because there are lots of things to take into account, from the type of algae you want to eliminate to the price of the product. This buying guide can help you identify the best pool algaecide for your pool.

What is algae?

Algae is the general name given to a large number of aquatic microorganisms that can conduct photosynthesis. You may be familiar with some types of algae such as seaweed or pond scum. The vast majority of algae live in aquatic habitats, and they are essential for the wellbeing of all forms of life that live in the water.

When it comes to pools, however, algae are more of a nuisance, and definitely not something you want to see near you when you’re enjoying a swim. As such, getting rid of algae is on the top of the list of every pool owner, so it’s important to identify what types of algae have found their way into your pool and purchase the correct type of algaecide to eliminate them.

Features to consider while buying the best pool algaecide

5 Best Pool Algaecides - Easy Problem Solution

Besides the type of algae that you want to exterminate from your pool, there are other essential factors to take into account when browsing through the multiple types of algaecide available on the market. These include the lasting period, foaming, clarifying, stain removing, and price.

Type of algae

Multiple types of algae can find refuge in pools, and while there are algaecide available on the market that are efficient against them all, some products only work on particular types of algae, so it’s important to identify them before purchasing a product.

  • Green algae — this is the most common type of algae that is to be found in pools across the country. You can often observe them floating in the water, but sometimes they may appear on the walls of the pool as well. When you have green algae in the pool, the water becomes less clear and you are likely to observe it also has a greenish tint.
  • Yellow/mustard algae — this type of algae is much more difficult to fight because it has a tendency of coming back even after you use products that make it disappear initially. If you have yellow algae in the pool, you need to take immediate action.
  • Black algae — this is by far the most difficult kind of algae to tackle because its roots can extend into grout or plaster. You can easily spot this type of algae because it looks similar to tar.
  • Pink algae — appearing in small spot, pink algae is similar to fungus and can generally be found in the corners, cracks, and crevices of the pool.

Each of these kinds of algae can be eliminated and their reoccurrence prevented with the help of algaecide. Some of the products we reviewed, such as the PoolRx Pool Unit #101066, our editor’s choice, are suitable for all types of algae, so they should be the first port of call especially if you’re not sure what kind of algae you’re dealing with or if you have more than one type in your pool or spa.

Lasting period

The lasting period refers to the amount of time the product is effective after you apply it to the water in the pool. There’s nothing more frustrating than using a pool algaecide only to find regrowth the next week. Most of the products we reviewed and included in our top guarantee 90-day protection, but some of them are more efficient than others. The PoolRx Pool Unit #101066, our editor’s choice, for example, has an extended six-month lasting period.


5 Best Pool Algaecides - Easy Problem Solution

As you want to protect your pool from algae throughout the season, look for products whose effects last for at least three months. The same rule works for water tanks in water rowing machines, because normally users don’t like to change water in them too often.

If you are looking for a product that you can apply before closing the pool for winter, a 6-month lasting one would be a good choice, such as the PoolRx Pool Unit #101066.

Stain removing

Some algae can stain the pool, but you can easily solve that problem with the help of an algaecide that eliminates stains. Keep in mind that copper-based algaecides can stain the pools themselves, so use them carefully.


Low-quality algaecides tend to add foam on the surface of the pool after you use it, and this can be rather annoying, as you don’t want to do the extra work of removing the foam together with the dead algae. You can avoid the extra hassle by choosing a product with a non-foaming formula, which allows the water to clear quickly, which means that you don’t have to wait for a long time before being able to take a dip in the pool. In order to be able to prevent foaming altogether, it’s essential to apply the product according to the instructions provided by the producer.


Most users want their water to be crystal-clear after they use an algaecide, so if you’re one of them, look for a product that clarifies the water as it eliminates the algae.


The price of pool algaecide depends on the quality of the product and the quantity you receive. Some products such as the Pool Mate 1-2150-02 only come in two 1-quart bottles, for example, so the total price you pay may be higher than in the case of other products.

Extra features

5 Best Pool Algaecides - Easy Problem Solution

You may want to look at extra features when shopping for pool algaecide, with Pool Mate 1-2150-02. For example, featuring a non-metallic formula. If you want to use the algaecide in a saltwater pool, look for a product that is particularly designed for that purpose, such as the Kem-Tek KTK-50-0006, for example.

Pool algaecide usage tips

When using pool algaecides, it’s always a good idea to go through the instructions provided by the manufacturer carefully. You should also make sure that the circulation system of your pool is in good working order and be careful to keep the sanitizer within the recommended range.

To keep the pool in tip-top condition, you should also shock the pool weekly, as this can eliminate the algae the algaecide products might have missed.

Using a good brush to scrub the walls of the pool is a good idea if you want to keep the algae at bay, but you should also use a vacuum to help dislodge the algae spores that may settle on the wall and the bottom of the pool.


To determine how much algaecide to add to your pool to get rid of algae, you should read the instructions provided by the manufacturer. The regular dosage that most of them recommend is written per 10,000 gallons of water, so take into account the size of your pool to be able to determine how much algaecide you need to add. Different products may have dosages listed for weekly maintenance or for severe infestations.

If used correctly and always according to the instructions of the manufacturer, algaecides can work in ponds. They are generally safe for fish and plants, as the chemicals they contain are not strong enough to impact pond life negatively. Most manufacturers recommend that you should aerate your pond heavily to prevent suffocation if you plan on using algaecides in them.

Our Verdict

We made the search for the best pool algaecide easier by reviewing dozens of products and selecting just the best of them to be featured in our top. We chose to feature the PoolRx Pool Unit #101066 as our editor’s choice because this is a highly potent product that works in all kinds of pools, including saltwater ones, and can fight against all types of algae. It also has an extended 6-month period. The Kem-Tek KTK-50-0006 come in second place, and it’s an excellent choice for those looking for a powerful algaecide that can eliminate green algae from their pools. This product has a no foaming formula and is compatible with salt systems as well. Finally, if you are looking for the best pool algaecide with a budget-friendly price tag, look no further than the SeaKlear algaecide, which is suitable for all types of algae and has a non-foaming formula that is also efficient in saltwater.

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