The Best Pool Algaecide

Dealing with algae in your pool can be frustrating, as this stubborn growth can quickly turn your water green and cloudy. While chlorine helps, it’s not always enough to combat algae. This is where algaecide comes into play – it’s not a miracle solution, but when used correctly, it can provide excellent results in conjunction with your regular pool maintenance chemicals.

Choosing the right algaecide can be confusing, especially for new pool owners. That’s why we’re here to guide you in selecting the best algaecide for your pool. Before we dive into recommendations, let’s understand the basics: different types of algae and algaecide options. This knowledge will help you make informed decisions to keep your pool clean and enjoyable.

What is Pool Algaecide?

Algacides are chemicals used to combat algae growth on pool walls, floors, pool steps, and even in pool water. Most agents previously used as algaecides – e.g. those based on atrazine or dichlorphene – are now banned because they can accumulate in water in the food chain and then be found in high concentrations in fish.

The same thing also applies to algaecides made from heavy metals such as copper sulfate or copper chelate. The use of algaecides containing copper has long been prohibited in running water, lakes and ponds, but is still sometimes used in swimming pools.

In contrast, algaecides based on benzalkonium chloride, sodium carbonate peroxyhydrate, or aluminum chloride hydroxy sulfate are widely used today in public and private swimming pools.

How Algaecides Work

Algaecides attack and kill algal cells by destroying cell walls, destroying chlorophyll, or attacking other cell organs. But in many cases, the exact effect cannot be explained.

Algaecides alone are not a panacea for algae in ponds because dead algae will disintegrate and decompose in the water. Thus, phosphate is released, which serves as algal food for new algae.

Another group of chemicals is used to disinfect pool water thereby preventing algae, bacteria and fungi from settling in the pool. Otherwise, the pool will turn green in a short time, and swimming time will run out.

This makes it clear that having a bacteria and algae free pond in the long term can only be successful if there is an interaction between;

• Algaecides to kill microorganisms
• Disinfect chemicals such as pool chlorine to prevent new infestations
• A mechanical device for removing and suctioning dead microorganisms.

Types of Algae

The following types of algae are most commonly found in ponds:

Green algae

Green algae is by far the most common type of algae found in swimming pools. They get into pools if toys or swimsuits are not cleaned thoroughly after swimming in a lake or river, thereby carrying the algae. Green algae makes pool water greenish. The color tone becomes more intense if there is a lot of algae.

Spherical green algae of the genus Chlorella are one of the most common floating algae in fresh water. They are suspended by gas vacuoles or remain in the water with floating appendages.

Green algae of the genus Scenedesmus, which are also common in fresh water, form clusters of 4 cells, each with a long floating appendage.

When they reproduce in large numbers, green algae form large masses that gather on the surface of the water as slimy green algae blooms. It shouldn’t have come to that! At the latest, if the water in the pool turns green and cloudy, you should intervene.

As filamentous colonies, when they grow on pool walls and floors, they look slippery and disgusting, and can cause a person to slip.

Cladophora algae is also one of the most common filamentous green algae found on the surface of water. They form a thin layer or clump together to form a cotton-like mass of algae.

Blue-green algae

This algae is not algae but bacteria, and does not have a cell nucleus. However, like algae, they drive photosynthesis with chlorophyll.

However, this green chlorophyll is covered by blue and red pigments. This is why they do not appear green like normal algae, but rather greenish blue with a metallic sheen.

This algae can absorb carbon dioxide for photosynthesis – this algae is harmless. But there are also blue-green algae that release toxic sulfur compounds into the water instead of oxygen. The third group of algae emits toxic ammonia and ammonium.

Here’s how it starts: Tiny blue-green algae of the genus Microcystis gather to form clusters of cells, clump together and then form algal clumps.

Although algae growth is primarily an aesthetic problem, mass colonies of these algae are a threat to our health. It is not for nothing that the lake is closed for bathing when there is a mass increase in blue-green algae.

If there is blue-green algae growth in the swimming pool – e.g. If the pool has not been used for a long time and the water has not been cleaned and filtered – then action must be taken immediately. In this case, thorough mechanical cleaning and subsequent shock chlorination of the water are essential!

Black beard algae

Black beard algae doesn’t appear much in swimming pools because there won’t be many black algae infestations if the pool is well maintained. They are the most problematic type of algae. Difficult to remove, you will have to carry out mechanical cleaning combined with chemical measures to remove pool algae.

Sometimes they are also referred to as black algae, although they are included in the red algae. However, they can become part of the algae growth on the pool walls and cause long-term damage to the concrete walls with their roots.

Therefore, they must be removed thoroughly: The best way is to kill them with black algae chemicals, loosen them with a steel brush, scrape them off, and then suck them up with a handheld vacuum cleaner.

Yellow algae or mustard algae

Yellow algae (scientific for Xanthophyceae) are the closest relatives of green algae but have a slightly different color pigment composition; that’s why the color looks more yellowish than green. Mustard algae in ponds occurs less frequently, is more persistent and difficult to remove.

This yellow or mustard algae first settles in the biofilm, growing on the walls of the pool and multiplying into a slimy yellow mass. Then they gradually detach themselves from the walls and turn the pool water yellowish.

However, this should not happen because this disease cannot be eradicated with commonly used chlorine-based algaecides. Additionally, this mustard coating also lasts outside the pool and can adhere to pool accessories, platforms, and steps.

Therefore, mechanical cleaning and thorough vacuuming of the pool walls becomes even more important.

Our Top 3 Recommendations

Overall Best Pool Algaecide – Clorox 32 oz Pool & Spa Algae Eliminator²

Runner Up – HTH 67032 Super Algae Guard 1 Qt Swimming Pool Algaecide

Best Quality – Clorox Pool & Spa 43128CLX 42128CLX Pool Algaecide

Best Pool Algaecides: Our Top 10 Pick

Some of the best pool algaecides on the market are listed and reviewed below. But first, take a look at our top 3 selections.

1. Clorox 32 oz Pool and Spa Green Algae Eliminator² – Overall Best Pool Algaecide

Clorox isn’t new to formulating pool chemicals. Their Pool & Spa Algae Eliminator is a non-foaming formula and is ideal for all pool types, whether salt or chlorine.

This formula works efficiently on green algae, the most common algae type. Moreover, it does not take much. You only need some ounces in a normal-sized pool.

The fast-acting formula is ideal for preventing and killing algae and leaves the swimming pool water crystal clear.

Pros

• Non-foaming formula
• Effective for killing and preventing algae
• Suitable for saltwater pools
• Kills green and yellow algae
• Ideal for all pool types

Cons

• The chemical smell

2. HTH 67032 Super Algae Guard 1 Qt Swimming Pool Algaecide – Runner Up

The HTH Super Algae Guard is a pool algaecide that is ideal for use if you are fighting less ordinary algae like the black algae or yellowish algae. It will also eliminate and prevent ordinary algae but is intended to fight stronger algae problems.

In addition to being more powerful than many other algaecides, the HTH Algae Guard is a superb preventative treatment which will last up to 90 days following treatment. Yet it is safe to bathe in the water 15 minutes after application. You only need about 1 fluid ounce for every 10,000 gallons of pool water.

Pros

• Works for more stubborn algae
• Good for algae prevention and elimination
• Has built-in clarifier
• Fast-acting
• Ideal for all pool surfaces and all types of algae
• You can swim immediately

Cons

• Foams a bit
• Strong chemical smell

3. Clorox Pool and Spa 43128CLX 42128CLX Pool Algaecide – Best Quality

Similar to the first Clorox algaecide reviewed earlier, the product is safe and ideal for all pool types, including spas. It is salt pool compatible. The algaecide ensures that the swimming pool is clear for weeks.

The Clorox Pool Spa algaecide and clarifier is also ideal for green algae. It does a wonderful job removing cloudiness that all these seaweeds can cause.

Pros

• A 2-in-1 product; algaecide and clarifier
• Provides exceptional algae control power
• Improves pool’s water quality
• Long-lasting effects
• Salt pool compatible

Cons

• You need more of the formula to get good results

4. McGrayel Algatec 10064 64-Ounce Super Algaecide for Yellow, Green, and Black Algae

The Algatec 10064 is a super pool algaecide from McGrayel. The name may not be familiar to you yet, but their superb algaecide packs a lot of punch. The formula works with other chemicals without throwing the elements off balance.

The non-foaming algaecide uses biostatic inhibitors to prevent dead algae from growing again or creating new algae blooms.

Algatec will even kill all kinds of algae and pests, interacting with the chlorine to protect and sanitize. It’s ideal for fighting green, black, and yellow algae. Plus, it works as a clarifier that leaves the swimming pool sparkling clean.

Pros

• Doesn’t interfere with pool water pH
• Uses biostatic inhibitors to prevent algae regrowth
• Ideal for all types of algae
• Non-foaming formula
• Superior algae fighting power

Cons

• You may need the whole bottle for each treatment

5. Clorox Pool Spa XtraBlue Pool Shock

The third Clorox Pool & Spa product on our list, the Pool Spa XtraBlue algaecide is an algaecide combined with bactericide. The pool shock is more of a very powerful biocide than anything else.

The Pool Spa XtraBlue algaecide should be used in swimming pools where aggressive treatment is needed, and the pool cannot be used while pool shock treatment is being applied.

You will see results in the very first week, and you can enter the pool water 15 minutes after adding the algaecide. The price of the Clorox Pool Spa XtraBlue is the highest of all the products here so far, although it is quite understandable why it’s a bit pricey.

Pros

• Powerful chlorine shock treatment
• High impact algaecide and bactericide and fungicide
• Improves filter performance
• Ensures pool is ready in 15 minutes

Cons

• Algaecide action reduced by sunlight

6. Kem-Tek Pool and Spa 60% Concentrated Algaecide

The Kem-Tek Pool and Spa Algaecide model does’t just eradicate algae. Additionally, it also prevents potential infestations. It is the strongest polymer algaecide for use in the pool, so it’s ideal for algae that are immune to chemical treatments.

Since it’s so powerful, however, you need to be careful. The pool and spa algaecide has 60% algaecide concentrate and contains ethylene dichloride which is hazardous to humans and animals, according to the EPA and the label on the product.

Follow manufacturer’s application instructions and do not swim in the pool until it is fully circulated.

Pros

• Algaecide compatible with salt system
• Stops algae growth and prevents regrowth
• Also clarifies pool water

Cons

• Hazardous to humans and animals

7. In The Swim 1/2 Gallon Super Pool Algaecide

The In The Swim Super Pool Algaecide lives up to its name. The algaecide is highly concentrated and super effective at removing all kinds of algae in all kinds of water. Formulated to prevent the pool from staining, the swimming pool algaecide contains 7.1 percent of Chelated Copper.

The active ingredient in this algaecide is aluminum, which has proven to be a fast and powerful substance in killing algae spores and preventing expansion. However, the same ingredient can make it unsafe for drinking, so make sure you’re only applying the chemical in only with the one you’re swimming in!

Pros

• Specially formulated for controlling mustard algae
• Non-foaming formula, no-smell algaecide
• Prevents pool wall staining

Cons

• Not sold in California

8. Pool RX 101066 6 Month Algaecide Treats 20k-30k gallons

The Pool RX mineral technology is ideal for all chlorine, salt, UV, and ozone systems. It ensures crystal clear water with less use of chemicals. The black pool unit is registered by the EPA and has an NSF/ANSI 50 certification. The pool algaecide supports 20,000 to 30,000 gallons of pool water.

Pros

• Doesn’t stain pool surface
• Ideal for eliminating all types of algae
• Also suitable for salt pools
• Turns green pool to clear pool
• Simple to install
• Helps balance pool chemistry

Cons

• You may start getting algae in your pool in 30 days

9. Pool RX 6 Month Blue Algaecide for Treating 7.5k to 20k Gallons

Pool RX again sets the record with its Blue algaecide solution. This is similar to the Pool RX 101066. However, it can only treat smaller pools with a capacity of around 7,500 to 20,000 gallons. Why it’s different is that it’s powerful on all kinds of algae, such as green, mustard, and black algae.

It’s also incredibly powerful, fast, and user-friendly. Reviewers say they can simply drop the item and dive straight into a completely clean and clear pool in a day. It’s said to be effective in swimming pools for 60 days.

Pros

• Turns a green pool crystal clear between a day to three
• Ideal for saltwater pool
• Ensures crystal clear water

Cons

• Does not last for 60 days but it’s very effective

10. SeaKlear 90-Day Pool Algaecide for Algae Prevention and Removal

SeaKlear provides a 90-day warranty with its algaecide, which means you won’t find other algae in your pool for three months or more. This is, of course, assuming you follow the instructions and use them correctly.

This product contains aluminum, so it is powerful from blue-green, green, black, black, and mustard algae. Plus, it won’t foam or stain your pool surfaces, no matter which pools type you have.

The blue liquid pool algaecide is reliable and effective and comes with a 90-day no-algae guarantee. It contains 11.8 percent copper sulfate pentahydrate and 3 percent copper.

Pros

• 90-day no-algae guarantee
• For killing and preventing yellow, green, and black algae
• Doesn’t foam or stain the pool

Cons

• Not so effective for black algae

Factors to Consider When Purchasing Algaecides

There are several criteria to consider before choosing the best pond algaecide for you. However, the type of algae you are dealing with is one of the most important considerations.

Types of pond algae

You’ll notice that some of the products in this review contain aluminum, which can be a powerful ingredient for black algae, as well as many other products that are difficult to remove.

The formula will also knock out other algae, but the compound may be harsher than you want if you’re just dealing with regular algae. However, most other algaecides are ammonia based, ideal for regular pond algae or fairly small infestations, but work ideally on yellow algae growths. Of the tens of thousands of algae species, swimming pool experts only have to deal with a few species in 99% of cases.

Price

Cost is always a criterion for considering everything we buy. However, most swimming pool algaecides are very affordable and long-lasting.

For a relatively decent price, you can save yourself a headache in the future.

Long duration

Additionally, start looking for products that are long-lasting. We usually only recommend products that can remove and protect against algae for at least 90 days. But if you have a strain that is harder to kill, you often have to maintain your pool regularly and keep using it for a shorter period of time.

For fresh water or salt water pools?

The best pond algaecides are compatible with saltwater, freshwater, and other types of pond water. It is recommended that you purchase what is appropriate for your pool system for best pool performance and to prevent damage to your pool materials.

Spotless

Non-foaming and stain-free qualities are very important factors for most pool owners who use algaecides. Formulas containing copper can sometimes stain your pool, but this is unavoidable if you are dealing with a tough pest infestation.

Clarifying

Finally, decide whether you want the product to include a clarifier. Many algaecides will turn the water slightly cloudy after application. Algacides with clarifying action will leave your pool crystal clear after treating pool algae attacks.

Conclusion

Maintaining a pristine swimming pool, free from the incessant intrusion of algae, can pose an ongoing challenge. However, diligent maintenance and strategic use of our premium swimming pool algaecides can turn this difficult task into a breeze, resulting in a sparkling clean pool and significantly reducing maintenance efforts.

For many swimming pool enthusiasts, the realization dawns that relying on chlorine alone may not be able to effectively control algae infestations, especially if their pool has experienced numerous disease outbreaks. Implementing an algaecide incorporation into your regular pool maintenance routine is emerging as the most powerful solution to combat this persistent threat.

In short, the quest for the perfect swimming pool experience is characterized by an unwavering commitment to fighting algae, and our exceptional algaecide products stand as formidable allies in this never-ending battle.

Wise Reviewer