How to Clear a Green Pool in 5 Days or Less

One of the most irritating moments for pool owners is getting ready for a quick dip in the pool on a hot sunny morning only to find out that the water is contaminated and has turned green. Although a green pool isn’t much to be worried about, it looks not only unhygienic but also unappealing, ruining the whole appeal of your backyard.

Why does it happen, even though you remember leaving crystal clear water the preceding day?

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Well, the answer is algae. If your water isn’t chlorinated well enough, you can see algae growth all over your pool overnight – especially if you live in a hot area like Arizona! The best way of keeping your pool water clear is by regulating the level of chlorine in it, which can be done quickly by adding chlorine tablets.

However, what to do if your water is already green? Is there no option other than replacing the water?

Fortunately, that’s what we’re here to discuss today; the greatest green pool algaecides you can find in 2023. Here, you’ll find # of our top picks out there to clean your pool water out and a user guide to help you get the most out of your purchase.

So, let’s take a deep dive into the green pool!

Here Are the Best Green Pool Algaecides

Clorox Pool&Spa Super Water Clarifier 32 oz

This is one of the best-selling algicides that you can buy right now. The product kills all algae in your pool without forming any non-foaming on top, thus giving you crystal clear waters at the end of the day.


  • Packing Dimensions: 3.1 x 3.1 x 10 inches
  • Weight: 2 pounds
  • Size: 1 Quart


  • Cost-effective
  • Effects last up to a week
  • Suitable for every pool type
  • Non-foaming


  • Need to use chlorine tablets along with it as well
  • Not as responsive for all water types (country-side well water, for example)


Using this green pool algaecide is as simple as pouring it near the walls, and best of all, it’s long-lasting, meaning you don’t have to use it every day but just once a week. Pour 1.5 fl. Ounces per every 10,000 gallons for best results.

hth Pool Algaecide Super Algae Guard

With an attractive price tag without compromising on quality, this green pool algaecide can kill more than just the green algae but also help you get rid of black and yellow algae.


  • Packing Dimensions: 4.6 x 2.6 x 9.1 inches
  • Weight: 2.25 pounds


  • Cost-effective and great value for money
  • Kills all types of bacteria


  • Not as long-lasting
  • Not suitable for pools in which water doesn’t circulate
  • Might foam in extreme temperatures


Using this algaecide is simple; pour it along the walls and see it work its magic. Just make sure you have a skimmer nearby since customers have often complained that the product foams a little. Most of it becomes crystals and settles, making it easier to clean up.

CLOROX Pool&Spa Algaecide + Clarifier CLX

This green pool algaecide is more than what it seems, clarifying the water in the process as well. It is slightly expensive to purchase, but it’s worth it, considering the strength and quantity. And again, it is backed up by Clorox, so you can expect it to be high-quality.


  • Packing Dimensions: 6.3 x 6.3 x 11.1 inches
  • Weight: 7.55 pounds


  • Suitable for all types of pools
  • Works as a green pool algaecide as well as a clarifier.


  • Costly when compared to others, but is bigger in size and quantity.
  • Results might not be as long-lasting


This is a non-foaming formula, so you can use it without having to worry about over-using, however, we recommend taking reasonable care. It is ideal not just for pools but also for spas and jacuzzies.

PoolRx Pool Unit #101066 6 Month Algaecide

With the ability to treat 30,000 gallons of water for up to 6 months straight, this is another good contender for our best green pool algaecides lists.


  • Packing Dimensions: 3.2 x 3.2 x 4.2 inches
  • Weight: 1 pound
  • Color: Black


  • Very effective and powerful
  • Long-lasting – lasts for six months
  • Non-foaming
  • Reduces other chemical usage (doesn’t eliminate it)
  • Easy to use


  • Costly
  • Some other similar units last longer


Using this unit is as simple as peeling the wrapper and placing it in the water. The rest, it will do on its own. It can also be used in spas, jacuzzies, and other pool types.

Clorox Pool&Spa XtraBlue Algaecide

Not to be confused with its cousin above, this is another contender for our best green pool algaecides by Clorox. Not only does it feature the brand name synonymous with trust, but it is also a good all-in-one algae solution for your pool.


  • Packing Dimensions: 3.7 x 3.7 x 10.3 inches
  • Weight: 2.5 pounds


  • Suitable for large and small pools alike
  • Kills all types of algae
  • Cost-effective and good value for money


  • Takes much more time than its competitors
  • Due to high demand, availability suffers from time to time
  • Overuse might lead to foam creation


This green pool algaecide is very easy to use; simply pour around the corners but make sure you don’t overuse it, since doing so might lead to foam in your pool. It can treat up to 25,000 gallons of water easily.

Buying Guide for the Best Green Pool Algaecides

Now, knowing what type of green pool algaecide is best is one thing; knowing which one suits your needs is entirely another. Here are two primary things you should consider before making a purchase.

Types of Pool Algae

The following are the more common types of Algae:

  • Green Algae – Aka the blue-green algae, these are what you find most of the time thriving in your pool.
  • Yellow Algae – Aka the yellow-green or mustard algae, these thrive without sunlight and are chlorine resistant most of the time.
  • Black Algae – This alga thrives in plaster pools, growing roots through the plaster. These are also chlorine resistant, along with the majority of algaecides.
  • Red Algae – Aka pink slime, this is another chlorine resistant algae that thrive in sunlight but can survive without it too. It is more common in colder climates.

How Green Pool Algaecides Work

Algaecides target small, singular blooms in order to prevent algae development or halt it further. Each algaecide functions differently, and here are how some of the common ones perform their function;

  • Quat Pool Algaecides – Also known as Quaternary Ammonium compounds, these algaecides are more like detergents. For these, it is important to have circulating water, and their detergent-type nature means overuse can lead to foaming. These algaecides attach to algae, destroying the outermost layer that protects them from chlorine. Once disintegrated, the chlorine can penetrate the algae and get rid of it.
  • Polymer Pool Algaecides – These algaecides are poly-quat elements forming long chains of carbon atoms. They don’t foam and are positively charged. As they come in contact with algae’s cover, they neutralize it, letting chlorine do its job properly. These algaecides last much longer than Quat and are therefore more expensive.
  • Metallic Pool Algaecides – These are the most expensive algaecides out there, but also the most effective ones. They follow the age-old trick of using copper ions for treating water. These not only clear up the water by bonding with amino acids in the water but also deteriorate the outer cover of algae and let chlorine do the rest.


Anyone who has ever dealt with a green pool knows how much of a nuisance they can be, not to mention the trouble they may cause when trying to clean them. It doesn’t matter if you just want to keep the pool clear or if the water has turned green from algae growth, algaecides can help.

If you’re having trouble keeping your pool water clear during the hot summer months, consider using one of the green pool algaecides we’ve listed above.

Related – Top 7 Above Ground Pools


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