Best Chlorine Tablets: A Review & Buying Guide



Keeping your swimming pool sparkling and clear often feels like a chore, fighting off the green tinge and unsafe bacteria which is always threatening to return.

Unless you start using chlorine tablets. Not only do they sanitize your water and make it safe for the entire family to swim, but they’re also super easy to use.

Read on and discover why not all chlorine tablets are created equal, and what you need to look for when choosing the best chlorine tablets for your swimming pool.

Top 6 Picks for Chlorine Tablets

We hand-picked the following pool test kits based on their popularity, price-points and differentiating features.

A more complete review of each can be found later in this article, or you can just click here to jump straight to that section.

Preview Product
Clorox Pool&Spa Active99 3”... Clorox Pool&Spa Active99 3”...
In The Swim 3 Inch Stabilized... In The Swim 3 Inch Stabilized...
Rx Clear Stabilized Granular... Rx Clear Stabilized Granular...
poolking Pool Care 3” Chlorine... poolking Pool Care 3” Chlorine...

What is a Chlorine Tablet?

Chlorine is a chemical which pool owners can use to treat their swimming pools, preventing algae and bacteria forming in the still waters.

Chlorine tablets are a dried version of this chemical, pressed and formed into a dense tablet form. They are also a tad fragile and can break and shatter if you drop them.

Many people complain about breakage, especially the dust that forms inside containers of chlorine tablets. It’s not safe to breathe, and you should also wear gloves to minimize any contact with your skin. While the chemicals are corrosive, chlorine pool tablets are your best option for sanitizing the water in your swimming pool.

Inserted into an automatic feeder, most chlorine tablets will last 7 to 10 days, as they slowly dissolve and release the right amount of chlorine needed into your swimming pool.

The best part is you won’t need to check and correct your water levels every day, you can just sit back and let the tablets go to work.

What Types of Chlorine Tablets Are There?

Swimming pool chlorine tablets come in a variety of forms and there are key differences to be aware of with each.

In this section, I’ll cover the different types of chlorine tablets you can buy for your pool as well as the benefits and drawbacks of each.

Stabilized Chlorine Tablets

The sun is the biggest enemy to chlorine. As direct sunlight shines UV rays straight into the water, it speeds up the rate chlorine dissolves in your pool.

The faster it dissolves, the quicker the positive effects (i.e. the sanitization) wears off. Which means you’ll need to add more chlorine to keep it safe for swimming.

So, pool companies quickly developed stabilized chlorine tablets. Most chlorine tablets are stabilized with the addition of extra chemicals to fight off the suns effects. Slowing the rate at which the tablets dissolve. Tablets that are stabilized will last longer in your pool.

Cyanuric acid is the chemical most commonly used as a stabilizer, which also helps to keep the water in your pool in balance.

Unstabilized Chlorine Tablets

You won’t be surprised to learn that unstabilized chlorine tablets are the opposite. Without the addition of a stabilizer like cyanuric acid, they dissolve far faster, especially on outdoor pools since they are exposed to the sun.

Most people will use unstabilized chlorine tablets to replicate a shock, that is, give their pool a strong dose of chlorine to fight off a major problem, yet have it dissolve quickly, so the chemicals don’t remain in the pool for long.

You could use unstabilized chlorine tablets for a quick treatment option during periods of heavy use, like over the kid’s’ summer break, but it requires a little more effort than the stabilized choice.

But Which Type Is Better?

Ultimately, it’s up to you.

Both types of chlorine tablets have their place, and will both serve to get your swimming pool sparkling clear. How they work is the difference.

Stabilized chlorine tablets are great if you need consistency in your pool. Perhaps your chlorine levels are already good, and you simply want to keep them this way.

On the other hand, if your pool is needing a shock or you want to boost your chlorine levels without dropping a bunch of extra cyanuric acid to the water, unstabilized chlorine is the way to go.

Smart pool owners will have both types of chlorine tablets on hand to cater to their pools every need, but if I have to choose a single option, I’d personally go with stabilized.

Not only does it make pool maintenance incredibly easy, but it also works even under the harsh rays of the summer sun, will save you costs (it doesn’t break down as fast), and removes one less task you’ve got to deal with after returning home from a long day’s work.

What Should you Look for in a Chlorine Tablet?

Knowing which type to look for will narrow down your options, but it doesn’t help you measure the nuances that make or break a product.

Let’s go over some of the main criteria you should apply to your decision making process when looking for the perfect set of chlorine tablets.

Tablet Size

Chlorine tablets typically come in just two sizes. 1-inch and 3-inch variations.

The tablet size you need to treat your water depends on just how big your swimming pool is, and the type of dispenser you are using. Some floating chlorine feeders will only hold a single chlorine tablet, bigger versions have space for several.

The number of tablets to use in your pool is easy to calculate. On the label, there will be a guide explaining how many of their tablets are needed per 10,000 gallons of water.

It’s usually just one or two, but best to check. Follow the instructions to ensure your pool gets the correct dosage.

Tablet Composition

You’ll find chlorine tablets composed of a many different chemicals, what’s important is to ensure there is around about 90% chlorine. I’d also recommend buying stabilized chlorine tablets, so they don’t dissolve too fast under the sun.

At these levels, your chlorine tablets will be most effective at killing algae, bacteria, yeast, fungus, viruses, and any other nasties which may be hiding in the water.

Tablet Dissolve Speed

The rate at which a chlorine tablet dissolves is one of the most critical aspects.

Too fast, and you risk “shocking” your pool with a hefty dose of chlorine in a short period of time. This renders your water unsafe for swimming until the chlorine dissipates.

Too slow, and you risk not having enough chlorine in your pool to keep the chemicals in balance, which quickly sends your pool an ugly shade of green.

Just like Goldilocks and her porridge, you need the perfect dissolve speed, which is about 7 to 10 days for a chlorine tablet to dissolve.

Tablet Packaging

Finally, it’s important to consider the packaging.

Most companies will individually wrap their chlorine tablets, especially in large containers. This helps to stop them breaking up, but it can make it a little messy because each will need to be unwrapped before use. And because chlorine is a rather strong chemical, you’re going to need gloves and perhaps even goggles and a mask to handle this fiddly task safely.

The size of the package will also play a role, as chlorine tablets are fragile, and will break if they are dropped or mistreated. When tablets are broken, they will dissolve faster, which is definitely not what you want as you’ll go through more tablets to achieve the same chemical balance in your pool.

Look for smaller package sizes, as the larger ones are more prone to being dropped and damaged during shipping.

Reviewing the 6 Best Chlorine Tablets

So far we’ve covered what chlorine tablets are, why you need one, the different types available, and what features to look out for.

In this section, we’ll be looking at specific tablet brands, each hand-picked for review based on the same criteria I’ve outlined in this guide.

Let’s get right into it.

#1. Swim Best 50 lbs Bucket 3″ Swimming Pool Chlorine Tablets, Stabilized

No products found.

Designed by Swim Best, these 3-inch tablets are 8 ounces each, and an excellent option for keeping your swimming pool in perfect condition throughout the year.

The active ingredient is concentrated 99% trichloro-s-triazinetrione, providing 90% available stabilized chlorine in tablets that are individually wrapped.

It’s one of the slowest-dissolving chlorine tablets you’ll find on the market, but what I love most is the price. Affordable and reliable, the only downside is they come in a 50-pound bucket, and some of the tablets inside may be damaged during shipping.


  • Individually wrapped and stored inside a second bag for added safety
  • Slow to dissolve to give a steady release of chlorine to your pool


  • Size of the container may result in damaged tablets

#2. CLOROX Pool&Spa 22005CLXW Active99 3″ Chlorinating Tablets

  • 99% Trichloro pool chlorine tablet that maintains...
  • Kills harmful bacteria
  • Long lasting sunlight protection

Designed by Clorox, these 3-inch chlorine tablets will help you to best enjoy your swimming pool, with minimal effort on your side.

The active ingredient is concentrated 99% trichloro-s-triazinetrione, providing 90% available stabilized chlorine in tablets that are 8 ounces each, and all individually wrapped.

What I like best is you can order bucket sizes from 5 pounds up to 35 pounds, which can result in less breakage (by buying the smaller containers). The only downside is the price, these are more expensive than some of your other options, though you could argue it’s worth it for less damage to the final product.


  • Slow to dissolve over 7 to 10 days with a steady release of chlorine
  • Waterproof container for storage is sturdy and durable


  • One of the more expensive options for chlorine tablets

#3. In The Swim 3 Inch Pool Chlorine Tablets 50 lbs.

  • Eliminate bacteria, algae, and other organic...
  • 99% Trichloro-S-Triazinetrione and 90% available...
  • Dissolve slower helping you to avoid inconsistent...

Designed by In The Swim, these chlorine tablets are the ideal size for most automatic feeders, floaters and skimmers, at 8 ounces per tablet, 3 inches in diameter.

The active ingredient is concentrated 99% trichloro-s-triazinetrione, providing 90% available stabilized chlorine allowing you to treat 10,000 gallons of water with just 1-2 tablets.

Even using two tablets a week, in the 50-pound container you’ll find roughly 114 tablets, which is more than enough for several months of use, depending of course on just how big your pool is. The only downside is they’re a little thicker than other tablets, which may affect how many you’re able to stack inside your automatic feeder.


  • Childproof lock on the bucket is a nice safety feature
  • Advertised as the longest lasting and slowest dissolving chlorine you will find


  • Size of the container may result in damaged tablets

#4. Rx Clear Stabilized Granular Chlorine

  • LONG LASTING - Dichlor resists UV light, lasting...
  • DISSOLVES QUICKLY - Add 1 oz of this cleaning...

Designed by RX, this granular chlorine is an alternative to the tablets as it comes in powdered form, but retains some of the slow-dissolving quality you get in chlorine tablets.

Available in containers from 8 pounds to 100 pounds, the active ingredient is 99.3% Sodium dichloro-s-triazinetrione dihydrate, providing 90% available stabilized chlorine.

What I like best with this treatment option is the chemicals dissolve in a gentle 4-foot column within your pool. It’s also not quite as harsh on your pool equipment, and won’t bleach your liner as some other products can.

The downside is the form. Being a powder, it will dissolve quicker than a typical tablet, and you may need to monitor your pool chemicals each day to ensure it stays in balance.


  • Less harsh on swimmers due to a different active ingredient
  • Different stabilizer in the compound is more resistant to UV rays


  • Can dissolve faster than other chlorine tablets

#5. Kem-Tek 2815-6 Chlorinating Tablets 1-Inch Pool and Spa Chemicals, 1.5-Pound

No products found.

Designed by Kem-Tek, these chlorine pool tablets are a compact option, perfect if you want an effective water treatment that won’t take up a ton of space in your garage, or need to quickly treat a smaller pop-up pool without investing in a lifetime’s worth of chlorine.

Coming in a container of just 1.5 pounds, inside you will find several 1-inch tablets that use an active ingredient of concentrated 95% trichloro-s-triazinetrione, providing 85% available stabilized chlorine.

What I like most is that you won’t get a strong smell of chlorine using these tablets, and they’ll last about a week in smaller pools. The only downside is the compact size, these are not ideal if you’re trying to treat a larger pool.


  • Perfect for stabilizing smaller, pop-up and above-ground pools
  • Slow dissolving tablets will provide constant chlorine levels up to 7 days


  • Need to be careful not to over-treat small pools and turn it cloudy

#6. NAVA Chlorinating Tablets for Swimming Pool/SPA

  • This NAVA 50-pound bucket of 3-inch chlorinating...
  • Individually wrapped
  • Concentrate

Designed by Nava, these chlorine pool tablets are 3 inches in diameter and are a great option when you’re wanting to eliminate the scum, algae and bacteria build up which makes a pool rather unappealing for a swim.

You’ve got the option to buy these tablets in containers ranging from 25 pounds to 100 pounds, ideal if you’re wanting to stock up and have a ready supply of chlorine over the coming summer.

The active ingredient is concentrated 99% trichloro-s-triazinetrione, providing 90% available stabilized chlorine in tablets that are 8 ounces each, and all individually wrapped.

What I like best is the price, these are an affordable option for anyone looking to keep their pool water clear on a budget. The only downside is the container lid, the child-proof latch can funnel water inside of the container and spoil your stock if you store it outside.  


  • One of the most cost-effective chlorine tablets options for your pool


  • Individual wrapping on the tablets is flimsy and breaks easily
  • The container needs to be stored inside, away from water

Our Winner(s)

While a close race, the chlorine pool tablets from In The Swim are the best you can buy because they’re just so easy to use. Slow to dissolve, you won’t have to be fiddling around with your pool chemicals more than once a week, and you’ll have more than enough stock to last you over the upcoming summer. Trust me, the easier it is to keep your pool maintained, the better.

The runner up

In close second is the most convenient option, the 1-inch tablets from Kem-Tek. Despite being smaller, they’re the perfect size for treating pop-up and above ground pools, without trying to break up the larger tablets or over-chlorinating your pool. Small, convenient, and easy to keep tucked in on a shelf in your garage until summer hits, they’re an excellent water treatment option if you’ve not got a large pool to care for.

If you want to keep your pool sparkling all summer long, you need the right chemicals to treat the water, ensuring it’s safe to swim. Chlorine pool tablets help to simplify this process, eliminating odors, killing bacteria and ensuring your water is crystal clear.

Skip the fuss, and choose the best chlorine tablets, so your pool is always ready for a swim.

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In this article, You will learn the reasons why not all chlorine tablets are created equal. Also, we will teach you what you need to look for when choosing the chlorine tablet products for keeping your swimming pool sparkling and clear. #chlorinetablets #poolonomics

Categories: Pool Care, Pool Chemistry