7 Best Pool Algaecides of 2021

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Best Pool Algaecides

Photo: Clorox

Algae is a common and perhaps the most annoying pool problem as it grows and spreads fast. While in most cases, the chlorine in the water can help keep it under control, you will still need to look for the best pool algaecide at some point.

Pool algaecides have a special formula that will kill algae, prevent it from forming, and help keep the water clear. As you shop for an algaecide, you first need to identify the algae type you are dealing with and look for a product that effectively kills and prevents it.

In this article, we explain how algaecides work, what to consider when shopping and review a few top options to give you recommendations.

7 Best Pool Algaecides - Review

IMAGE

PRODUCT

FEATURES

Pool RX 101001 Algaecide

1. Pool RX 101001 Algaecide (Best Overall)

  • 6-month effectiveness
  • Kills all algae types & bacteria
  • Minimizes pool chemical demands
McGrayel Algatec 10064 Super Algaecide

2. McGrayel Algatec 10064 Super Algaecide (Best for All Algae Types)

  • Kills & prevents green, yellow & black algae
  • Powerful clarifiers
  • No-wait time required
Kem-Tek KTK-50-0006 60% Concentrated Algaecide

3. Kem-Tek KTK-50-0006 60% Concentrated Algaecide (Best for Green Algae)

  • High potency with 60% concentration
  • Compatible with salt systems
  • Non-foaming formula
SeaKlear 90-Day Algae Prevention & Remover

4. SeaKlear 90-Day Algae Prevention & Remover

  • Kills and prevents all algae types
  • Non-foaming & non-staining
  • Provides a 90-day treatment
HTH 67032 Super Algae Guard Swimming Pool Algaecide Cleanser

5. HTH 67032 Super Algae Guard Swimming Pool Algaecide Cleanser

  • Safe on all pool surfaces & sanitization systems
  • Works for all algae types
  • Fast-acting formula
Clorox Pool&Spa Green Algae Eliminator2

6. Clorox Pool&Spa Green Algae Eliminator2

  • Fast-acting green algae treatment
  • Non-foaming formula
  • Salt pool compatible
Pool Mate 1-2150-02 50 Pool Algaecide

7. Pool Mate 1-2150-02 50 Pool Algaecide

  • Non-metallic formula
  • Effective against all algae types
  • Safe on all pool finish types

PRODUCT

1. Pool RX 101001 Algaecide

(Best Overall)

Pool RX 101001 Algaecide
  • 6-month effectiveness
  • Kills all algae types & bacteria
  • Minimizes pool chemical demands

2. McGrayel Algatec 10064 Super Algaecide

(Best for All Algae Types)

McGrayel Algatec 10064 Super Algaecide
  • Kills & prevents green, yellow & black algae
  • Powerful clarifiers
  • No-wait time required

3. Kem-Tek KTK-50-0006 60% Concentrated Algaecide

(Best for Green Algae)

Kem-Tek KTK-50-0006 60% Concentrated Algaecide
  • High potency with 60% concentration
  • Compatible with salt systems
  • Non-foaming formula

4. SeaKlear 90-Day Algae Prevention & Remover

SeaKlear 90-Day Algae Prevention & Remover
  • Kills and prevents all algae types
  • Non-foaming & non-staining
  • Provides a 90-day treatment

5. HTH 67032 Super Algae Guard Swimming Pool Algaecide Cleanser

HTH 67032 Super Algae Guard Swimming Pool Algaecide Cleanser
  • Safe on all pool surfaces & sanitization systems
  • Works for all algae types
  • Fast-acting formula

6. Clorox Pool&Spa Green Algae Eliminator2

Clorox Pool&Spa Green Algae Eliminator2
  • Fast-acting green algae treatment
  • Non-foaming formula
  • Salt pool compatible

7. Pool Mate 1-2150-02 50 Pool Algaecide

Pool Mate 1-2150-02 50 Pool Algaecide
  • Non-metallic formula
  • Effective against all algae types
  • Safe on all pool finish types

1. Best Overall: Pool RX 101001 Algaecide

Pool RX 101001 Algaecide

The Pool RX 101001 Algaecide is our best overall pool algaecide as it lasts longer in the pool, works for any pool type and will do much more than just getting rid of algae.

When you add this algaecide to the water, it will release a blend of minerals that will remain effective at algae control for up to 6 months. What's more, the algaecide will kill all types of algae and bacteria and reduce the pool's chemical demands significantly.

You can use this algaecide on any pool type you have as it is safe and effective on chlorine, UV, salt and ozone systems.

Also, it can work for almost any pool size. Besides this model that works for up to 20,000-gallon capacity pools, you can get the Pool RX 101066, which can work for pools with a 30,000-gallon capacity.

The only gripe some pool owners might have with this algaecide is the price. However, for the service length it provides and its effectiveness, it is worth every buck.

Pros

  • Lasts longer in the pool
  • Effective against all algae types
  • Helps reduce your pool's chemical demands
  • Safe for use on all types

Cons

  • A little pricier

2. Best for All Algae Types: McGrayel Algatec 10064 Super Algaecide

McGrayel Algatec 10064 Super Algaecide

McGrayel Algatec 10064 Super Algaecide is a powerful product that will kill and prevent green, yellow, and black algaecide formation. What makes it a highly effective treatment for these different algae is that it will kill instead of just starving them.

This algaecide will kill most of the algae in under 24 hours, and it should also get rid of the troublesome black algae in as little as 7 days. Moreover, this product does not interfere with pool pH or sanitizer levels, making it safe for immediate swimming.

The inclusion of some powerful clarifiers in the algaecide will always leave the water crystal clear. Other things that make this product fantastic are it is saltwater pool friendly, non-staining and non-foaming.

Using this algaecide comes with a lot of scrubbing, but the results make it worth putting in the extra elbow grease.

Pros

  • Effective against all algae types
  • Pool is ready for immediate use with no wait time
  • Leaves the water crystal clear
  • Salt pool friendly formula

Cons

  • Requires a lot of scrubbing
Kem-Tek KTK-50-0006 60% Concentrated Algaecide

Kem-Tek KTK-50-0006 is a highly potent algaecide with a 60% concentration. The higher concentration makes it an excellent solution when dealing with a problematic green algae infestation.

A little of this algaecide goes a long way, so you hardly ever need to use more than a couple of ounces for every 10,000 gallons of water. What's more, it is a long-lasting product that you can be sure will treat and prevent algae re-infestation for many months.

The formula is non-foaming, and this algaecide is also helpful for clarifying the water. Also, you can use it will most pools as it is also compatible with saltwater systems.

Despite being quite potent, this algaecide seems to struggle with certain algae types like the black algae. However, if you use it consistently and increase the dosage slightly, you can still remove most black algae infestations.

Pros

  • More potent to ensure can kill algae fast
  • Does not cause any foaming
  • Works with most systems, including saltwater
  • Effective at both algae treatment and prevention

Cons

  • Seems to work best for green algae only
SeaKlear 90-Day Algae Prevention & Remover

SeaKlear 90-Day Algae Prevention & Remover will kill algae and prevent it from forming again in the pool for up to 90 days. Also, the algaecide will work on all kinds of algae types as it is effective on green, black and mustard algae.

Besides keeping your water clear and algae-free for up to 3 months, this algaecide will also not cause any foaming. Moreover, it also does not stain no matter how long you keep using it, which is essential for maintaining overall pool aesthetics.

You can use this algaecide on all pool types as it is safe on different sanitization systems, including the saltwater, UV and ozone systems.

When it comes to the dosage, you will need at least 16 fluid ounces for every 10,000 gallons of water. But if the algae infestation is severe, you should use double that (32 fluid ounces).

This product seems to require quite a high dosage compared to others on our pool algaecide review. However, its smaller price tag and the fact it lasts for up to 3 months seem to make up for this.

Pros

  • Effective on most common pool algae types
  • Provides long-lasting protection
  • Does not foam or satin pool surfaces
  • Works for all pool types

Cons

  • High dosage required
HTH 67032 Super Algae Guard Swimming Pool Algaecide Cleanser

You need to think about your pool surfaces and sanitization system as you choose the best algaecide for pools. However, this should hardly be a concern for you with the HTH 67032 as it does not damage any surface and works for all systems, including the saltwater ones.

This algaecide kills all algae types, from green and yellow to the more troublesome black algae. Better still, you will not need to use a lot of it as just 1 fluid ounce is enough per 10,000 gallons of water every 3 to 5 days.

The formula is fast dissolving and will not make your water cloudy. With this algaecide, there is minimal downtime as your pool will be ready to use in as little as 15 minutes.

While this algaecide has a strong chemical smell, it does its job quite well, and the odor dissipates fast when you add it to the pool. Also, it still foams a little, but this does not affect its effectiveness.

Pros

  • Does not damage any pool surface or sanitization system
  • Kills and prevent all algae types
  • Dissolves fast without foaming
  • Minimal pool downtime

Cons

  • Strong chemical smell
  • Foams a little
Clorox Pool&Spa Green Algae Eliminator2

Green algae are the most common type you are likely to encounter in your pool. Hence, this Clorox algaecide will be very useful. Its formula is fast-acting, and it will kill the green algae in your pool in just a few hours.

It would help if you make this algaecide a part of your weekly routine maintenance for the best results, and you will only need around 1.5 fluid ounces for every 10,000 gallons of water.

There will not be any foaming on your pool when using this algaecide, and it also does not have that strong chemical smell that is typical of most others. What's more, you can use it with saltwater and most other pool sanitization system.

This pool algaecide does not seem very effective at preventing algae, but it does a fantastic job killing any new blooms.

Pros

  • Kills green algae fast
  • Does not cause any foaming
  • Works for saltwater and most other pool types
  • No strong scent

Cons

  • Not very good at algae prevention
Pool Mate 1-2150-02 50 Pool Algaecide

With the non-metallic formula of the Pool Mate 1-2150-02 50 Pool Algaecide, you can be confident it not will stain your pool surface or fixtures. This formulation also makes the algaecide safe for all pool types, including vinyl and gunite finishes.

You can use this algaecide to kill green, yellow, black or any other type of algae that forms in your pool, and it is also effective at preventing them from forming again.

A little of this algaecide goes a long way, and you will only need 2 to 3 fluid ounces per week for every 10,000 gallons of water.

This algaecide forms a few bubbles on the pool surface, but besides being a minor nuisance, they will not affect the effectiveness, and they seem to clear out fast. Also, the unpleasant smell should not be a deal-breaker as it dissipates quickly.

Pros

  • Formula does not stain pool surface
  • Kill and prevent all kinds of algae
  • Can work for all pool types
  • Low weekly maintenance dose

Cons

  • forms some bubbles
  • Unpleasant smell

Different Types of Algae 

Different Types of Algae

Before you start shopping for an algaecide, it is crucial to note that you can encounter different algae types in your pool. Knowing these different types will make it easier to decide what algaecide to buy. Here are the 3 most common pool algae types.

1. Green Algae

The green pool algae are the most common type and perhaps what most pool owners are likely to have to deal with at some point.

As this algae formins, you will often notice small clusters around the pool steps and in the corners or edges. However, it can grow to cover the entire pool in as little as 24 hours if you fail to remove the small clusters immediately.

A thorough scrub and a good pool algaecide are often enough to deal with green algae if you catch it early enough. However, it is also a great idea to shock the pool to ensure you resolve the issue altogether.

2. Yellow/Mustard Algae

Yellow algae are also what many pool owners refer to as mustard algae, given the dark mustard appearance. The algae will often grow in pools that are in shaded areas as they require less sunlight.

Getting rid of yellow algae is more complicated than green algae. Also, it tends to cling to pool fixtures and toys, which makes re-infestation easier. However, with persistent scrubbing and algaecide treatment, you can still keep it under control.

3. Black Algae

Black algae are the kind you do not want to ever get in your pool as it is the toughest to remove.

Although it still qualifies as pool algae, it is a bacterium that will thrive in any still water. It has thick cell walls that make it hard for chlorine and other pool sanitizers to penetrate.

Many potent algaecides out there can kill black algae, but it takes more time, and you often need several rounds of treatment.

How Does Algaecide Work? 

Algaecides will work by attacking the cell walls of the algae already in the pool to destroy them. Additionally, using them as part of your regular pool treatment and maintenance allows them to prevent any new blooms from growing and multiplying.

Adding the algaecide to the pool water will first damage the algae's cell walls. Destroying the cell walls will ensure the algae does not bloom and hence will not get the chance to multiply.

Also, if the algae are already blooming, the algaecide will kill the existing organisms by first attacking their cell walls.

However, it is essential to note that it will not do the job alone, regardless of the algaecide's potency. You need to ensure that your pool chemistry is in perfect balance by maintaining the pH, alkalinity and chlorine at optimal levels for the algaecide to be effective enough.

How to Buy the Best Pool Algaecide 

How to Buy the Best Pool Algaecide

1. Algaecide Type

Just like there are several kinds of algae you can encounter in your pool water, there are also many types of algaecides you can get out there. Therefore, as you shop for the best pool algaecide, you first need to understand the different types available.

Quat Pool Algaecide

These algaecides are just detergents for cleaning the pool water, and when you overuse them, you often end up with foamy pool water.

Like other kinds of detergents, they work by breaking down the algae. They will attach to the algae's cell wall and dissolve them to allow the pool sanitizer to get in and kill the organism.

This algaecide is the most common type and will have a concentration of up to 50%. Also, it will not stain the pool like other types, such as metallic pool algaecides.

Metallic Pool Algaecide

Metallic pool algaecides will contain some copper ions. These algaecides use the positively charged ions to attack algae cell walls and poison the cell's nucleus to kill the algae.

Although metallic pool algaecides are potent enough, the algae can develop resistance to it at some point and overusing them also stains the pool. These algaecides will have around 7% concentration, and they work best for black and green algae.

Polymer Pool Algaecide

Polymer pool algaecides are among the most potent as they can suffocate algae bloom twice as fast as the quat algaecides.

Additionally, the polymer pool algaecides do not foam and will also not stain your pool. They have a concentration of between 30% and 60%, but they tend to be more expensive.

Sodium Bromide

Sodium bromide is technically not an algaecide, but it is highly effective at keeping algae under control. It works together with the chlorine in the water.

Chlorine oxidizes the bromide in the compound as sodium dissolves to form hypobromous acid (HBrO), which is highly effective at preventing algae growth.

2. Dosage and Effectiveness Period

You will also need to consider the dosage and effectiveness period as they both affect the product's suitability.

Dosage determines how long the product will last and hence the value you get for your money. The higher the concentration, the smaller the amount of algaecide you need to use and therefore the better the value you get. For example, something that requires you to use 2 to 3 ounces for every 10,000 gallons of water is excellent.

Effective period is a good indication of how long the algaecide will protect your pool. Something that offers extended protection is always the best as it will save you money. That said, an algaecide that is effective for up to 6 months like the Pool RX 101001 Algaecide is perfect

3. Non-Foaming and Non-Staining

A good pool algaecide should not give you extra work of dealing with stains on pool surfaces or foamy water. Therefore, when deciding what to buy, it is always a good idea to go for something with a non-staining and non-foaming formula.

Most manufacturers will indicate whether their products foam or stain in the labelling. However, it is always better to look at the ingredients and read customer reviews to determine this for yourself, as some companies can be misleading with their labelling.

4. Price

Pool algaecides are relatively affordable when you compare them with other pool chemicals. However, their price still matters since you will need to use them often.

The right idea is not to go for the cheapest algaecide you can find. Instead, look for something that will give you the best value for money. Something with a high concentration that requires you to use just a little of it and lasts long in the pool is always the best.

Bottom Line 

You need to have the best pool algaecide as part of your routine pool maintenance kit. The good news is that there are more than enough options out there, and our review above should make it easier to narrow down your choices.

That said, the Pool RX 101001 Algaecide is our best overall recommendation as it kills all algae types, provides up to 6 months of protection and will also minimize the demand for other pool chemicals.

However, if your main issue is green algae, the Kem-Tek KTK-50-0006 60% Concentrated Algaecide will be a great choice as its formula is meant explicitly for this algae type.