The Best Chlorine Tablets for Swimming Pool

UPDATED: Jan 01, 2020.

To keep it sparkly and safe for the swimmers, every pool owner has to regularly chlorinate the pool water.

It’s actually chlorine that gives that funny taste to the pool water. However, it goes way beyond giving your pool the peculiar taste. From keeping your pool water clean to keeping your family healthy, chlorine does all the heavy lifting.

Chlorine tablets are arguably one of the most popular approaches to killing the viruses, bacteria, and protozoa in the stagnant water. In other words, the chlorine tablets prevent the formation of algae, keep the walls and floor clear of any stains, and remove bad odor.

However, not all the chlorine tablets are made equal.

The overabundance of products available in the market makes choosing the best chlorine tablets hard, especially if you don’t have any prior experience of maintaining your pool.

To make matters worse, most of the tablets look alike.

Which brand should you trust? Which chemical concentration is right? And more importantly, what are the best chlorine tablets for swimming pools?

To make your venture easy, we have come up with the list of top chlorine tablets after comparing nearly 40 different brands and models.

Tips on Choosing the Best Chorine Tablets

Choosing the right chlorine tablets for your pool can be a simple and straightforward if you keep these four factors in mind.

Calculate Chlorine Demand

Just as the name suggests, this is the amount of chlorine your pool needs to stay clean. Adding too little chlorine will result in some of the bacteria and scum evading chlorination. Adding too much will not only cost you more but may also make your water cloudy and can even adversely impact your pool equipment.

This is why it’s crucial to understand exactly how much chlorine your pool requires. This depends on the size and shape of the pool, and the amount of water in it. There are many ways to calculate the chlorine demand. However, you should consider investing in a good quality digital meter for accurate reading.

Stabilized vs. Unstabilized Chlorine Tablets

There are two main types of chlorine tablets available in the market. They are either stabilized or unstabilized tablets.

Stabilized chlorine can last longer, even in the sunshine. They actually perform better in the sun and thus are ideal for outdoor pools. Also, they’re equally effective for both in-ground and for above ground pool.

On the other hand, unstabilized chlorine tablets are ideal for hot tubs (or pools) that are located indoors or in shady areas. Since they are unstabilized, chlorine loses its impact faster if it gets direct sunlight.

Understanding the Chemistry

It’s time to brush up your chemistry skills from the days back in school.

The major ingredient of any brand or product of is always either trichloro-s-triazinetrione or trichlor. However, most manufacturers combine other chemicals to increase the life and longevity of the tablets, as well as to increase its potency to fight algae.

While these chemicals can make the tablets long last longer by slowing down the release of chlorine, some of these can reduce the overall effectiveness.

Understanding the ideal balance here can be a little tricky. But to make things easy to understand, if your pool stays clear and fresh most of the times, you should go with tablets with high trichlor concentration.

On the other hand, if you experience frequent algae formation and other issues, you might want to go with tablets that have a higher percentage of other algae fighting additives.

Price by Quantity

Chlorine tablets are not ridiculously expensive. But your overall pool maintenance usually comes with a hefty price tag. This is because it involves so many different components that they can add up at the end of the day.

So, wherever you can save a few bucks, it will eventually bring down the overall cost of maintenance.

We have made every effort to include only the most cost-effective chlorine tablets in our top 10 list, so you have complete peace of mind when shopping. But remember to compare the prices of two different products by quantity. This is because some manufacturers offer higher quantity than others which can make the comparison a little harder.

Here are our picks for The Best Chlorine Tablets for Swimming Pool:

• Best overall: Clorox Active 99
• Best cheap chlorine tablets: Kem Tek Chlorinating Tabs
• Best 3 inch chlorine tablets: In The Swim 3″ Pool Chlorine Tablets
• Best stabilized chlorine tablets: Rx Clear 1-Inch Chlorine Tablets

Here Are The Best-Selling Chlorine Tablets in 2020 – UPDATED

Here are the ten best chlorine tablet products based on our comprehensive research and our reader’s feedback. This means you use these products with confidence of knowing that many other pools owners like you are already benefiting from these.

Clorox Active 99

Pros

• Comes in a waterproof canister
• Works efficiently with highly active ingredients
• One tablet works well for 10,000 gallons of water
• Available in a variety of sizes

Cons

• A bit expensive

Available in a variety of sizes, Clorox Active 99 is among the most efficient tablets you can find for above ground pool.

You need to maintain 1 to 4 parts per million of chlorine to keep your water clean and clear. Clorox Active 99 helps you do just that, and you can achieve it by using 1 tablet at a time. However, you will have to keep adding more tablets to skimmer to maintain that percentage.

These tablets are also suitable for feeder or floater application. They are all wrapped in plastic, which makes handling a lot easier. These tablets take time to dissolve in the water, which means they stay active for long enough to offer added protection against bacteria and algae.

The product is safe to use but may be considered a bit expensive by some.

Verdict:

These pool chlorine tablets work efficiently to offer professional results. They take time to dissolve but keep your pool lean. The price is a bit on the higher side though.

Kem Tek Chlorinating Tabs

Pros

• Suitable for every pool sanitization
• Stabilized to prevent chlorine loss
• Slow-dissolving tablets
• Reasonable size for small above ground pools

Cons

• May make water a bit murky
• May need more for larger pools

What are the best chlorine tablets for swimming pools, you ask? Look no further than Kem Tek Chlorinating tablets. These tablets are suitable for most pools, including small above ground pools and pop up pools.

You can get the strip kind and use them while knowing how much chlorine is enough. These slow-dissolving tablets are suitable for long-lasting sanitation and maintain a steady chlorine residual.

Do not worry about chlorine loss to the UV rays since the tablets are stabilized. There is no need to use more than one at a time, especially for smaller pools. Using a water test kit is a good idea though because it tells you when to add more.

Keep in mind that it is important to change the filters once every two months, especially if you use these tablets often. Excessive use may leave the water murky and require you to drain it often. Nevertheless, draining is much better than using chemicals to get similar results.

Verdict:

Available in small 1-inch size, these tablets are easy to handle and offer long-lasting sanitation. You may have to change the filter often to continue getting good results.

Clorox Pool and Spa 6001 CLX Tabs

Pros

• Help you get rid of bacteria quite efficiently
• No need to worry about algae growth
• Quite suitable for pools of up to 5,000 gallons
• Smaller tablets suitable for smaller pools

Cons

• Maybe a bit expensive for some

Finding the right type of chlorine tablets for your small pool is no longer an issue with these Clorox tablets. It is an impressive product that works quite like commercial chlorine.

The product works great for pools of anywhere between 700 gallons and 5,000 gallons. The tablets target bacteria and prevent algae from growing into the pool. They also help eliminate the scale and dirty at the same time.

You may have to buy a small floater to make them work perfectly. All you have to do is put them in the floater and leave in the pool without removing the filter.

The tablets are also suitable for hot tubs. The product is going to last for a while because you do not need too many tablets per session.

Verdict

Using the tablets is a highly convenient way to keep your pool clean without raising concerns about your safety. The price could have been better though.

In The Swim 3″ Inch Pool Chlorine Tablets

Pros

• 90% available chlorine
• Suitable for 10,000 gallons of water 
• Slow dissolving 
• Size fits all floaters and feeders

Cons 

• The tablets might be broken in packing 

Look no further if you are in search of thick chlorine tablets. They dissolve slower and stay in the pool longer for lasting protection. The 3-inch size makes the tablets ideal for floaters and automatic feeders. The tablets are individually wrapped in easy to open bags.

Verdict 

These are industry-leading chlorine tablets consist of 90% available chlorine to provide long-lasting sanitizing power. 1 to 2 tablets will be enough for 10,000 gallons of water.

Rx Clear 1-Inch Stabilized Chlorine Tablets

Pros 

• 90% available chlorine and 99% Trichlor 
• Each tablet weighs 0.5 oz. 
• Slow dissolving 
• Great performance at a low cost 

Cons 

• More quantity is required for even smaller pools

Rx Clear 1″ stabilized chlorine tablets make your pool crystal clean without being harsh on your skin. The tablets contain 90% chlorine and 99% Trichlor. They are slow dissolving and do a reliable job in balancing the pool chemistry.  

Verdict 

Rx Clear 1″ stabilized chlorine tablets are highly effective in reducing the chemical mess from your pool. Up to 7 tablets are needed per 2,500 gallons of water. They are slow dissolving. You have to add them once a week.

Pool Brand 3-Inch Swimming Pool Chlorine Tablets

Pros

• Tablets are EPA approved 
• They are UV stabilized for an extended life 
• They are neither diluted nor blended 

Cons 

• They dissolve very quickly 

These 3-inch tablets promise to keep your pool sanitized. They are EPA approved. Each tablet consists of 90% available chlorine. The best quality of these tablets is they aren’t blended or diluted. This makes them highly effective in keeping your pool water clean.

However, many users have complained that the tablets dissolve quickly and it’s hard to keep the chlorine level right.

Verdict 

Each tablet is UV stabilized which extends their effectiveness. They are slow dissolving but they completely blend in the water to sanitize it. 

Cclear Pool Supply Pool Chlorine Floater for Chlorine Tablets

Pros

• It comes with a 2-year warranty 
• It’s constructed from heavy-duty material 
• Fits 1 to 3 inches tablets 
• It’s durable and easy to use 

Cons 

• This plastic floater is not the strongest 

Cclear pool supply pool chlorine floater is made from high-quality materials that don’t let it sink or break. It can hold up to 1 to 3-inches tablets. The adjustable twist-lock cap prevents tablets from falling out or staining the pool’s bottom. It is foam filled and it lets you make the most out of your chlorine tablets. 

Verdict 

Cclear pool supply pool chlorine floater is designed to increase the life of chlorine tablets and let you sanitize your pool water.

HTH Pool Sanitizer 1″ Chlorinating Tablets

Pros

• Kills bacteria, algae, and other harmful organisms 
• Sun protected to prevent chlorine loss
• Easy to use 
• Less quantity of tablets is required 

Cons 

• The tablets have a sharp bleach odor 

HTH chlorinating tablets are designed to keep your pool water clean and kill bacteria and algae. 1 tablet can treat up to 10, 000 gallons of water for up to a week. The tablets are sun protected to enhance their durability and effectiveness. You can toss them into the pool directly or place them in a skimmer, feeder or floater.

Verdict 

HTH chlorinating tablets help maintain a chlorine residual of 1- 4ppm. One tablet per 10,000 gallons of water is required to maintain clean pool water.

Nava Chlorine Large Tablets

Pros

• Effective for killing germs and bacteria 
• Concerted and stabilized 
• Easy to open and use 
• EPA approved 

Cons 

• These are not the best quality tablets out there

Nava 3-inch chlorine tablets keep your pool water clean all season long. A quality that sets these tablets apart is that they don’t cloud pool water. Place them through floater, feeder or skimmer. These tablets are concentrated, slow dissolving and they leave no mineral scale behind.

Verdict 

Nava chlorine tablets keep your pool water disinfected without clouding it. Since they are not the best quality tablets, they become brittle and that makes them dissolve in the water quicker.  

Star Plus 3-Inch Wrapped Chlorinating Tablets

Pros

• Solid performance 
• The tablets are stabilized 
• Their size is ideal 

Cons

• The tablets have a pungent smell 

Star Plus 3-inch chlorinating tablets are ideal in size. They easily fit automatic chlorine feeders and floating dispensers. As soon as you toss them into the pool, they start working to kill viruses, bacteria and other contaminants from the pool water. They contain 99% Trichlor. You can use them in both pools and spas.

Verdict 

Star Plus 3-inch chlorinating tablets hardly break in the packaging like other tablets. They stay in the pool water longer and they do their job of cleaning the water effectively.

Swim Best Trichlor Chlorinating Tablets

Pros

• Quite impressive in terms of spreading across the pool
• Offer long-lasting sanitation
• Slow-dissolving tablets for better performance

Cons

• Quite fragile
• Difficult to unwrap

Swim Best Bucket 3-inch tablets are quite effective for hot tubs as well as above ground pools. These are large enough to work well for larger swimming pools.

They dissolve quite slowly, so help keep the water disinfected for long. The tablets are extremely easy to use with skimmers, floaters, and feeders baskets. The slow-dissolving mechanism ensures that the ‘ingredients’ spread evenly across the pool.

They are efficient also because they are highly concentrated. Interestingly, they leave no mineral buildup in your pool or tub. These EPE certified tablets guarantee safety.

The only issue you may face is that these tablets are a bit fragile, which makes handling difficult. If you can unwrap them carefully, you will not have to worry about much though. Price is quite affordable too.

 Verdict

These highly concentrated tablets work efficiently to keep your pool disinfected for long. They are reasonably priced but feel a bit fragile at times.

In the Swim Stabilized Tablets

Pros

• Slow-dissolving tablets for long-lasting performance
• Highly concentrated with 99% trichloro-S-triazinetrione
• Stabilized for added protection against the UV rays
• Individually wrapped for easy handling

Cons

• May need a higher dose depending on the temperature of the pool
• Individual wrapping may not be sealed

The In the Swim 3-inch tablets are among the finest chlorinated tablets available in the market. They are highly concentrated with up to 99% of trichloro-S-triazinetrione. They also feature 90% stabilized chlorine to ensure that the chlorine loss to sunlight is minimal.

You can expect exceptional results simply by adding a couple of tablets to 10,000 gallons of water. The dosage is enough to keep your water disinfected for up to a week. These slow-dissolving tablets stay effective for long, but higher doses are needed depending on your pool’s temperature.

Using these tablets is easy too, as they are individually wrapped. You can order them in 50lb bucket, with about 114 tabs per bucket. It means a single bucket will last longer depending on how often you use them.

Be a bit careful when opening the bucket for the first time because individual wrapping may not be sealed properly. Open it in the outdoor to avoid inhaling fumes.

Keep in mind that the tablets are quite thick, so they may not be suitable for skimmers. They are quite suitable for floaters though.

Verdict

These affordable pills work efficiently and are easy to use with individual wrapping. The tabs are quite fragile though, so practice care when opening the bucket.

Leisure Time Non-Chlorine Shock

Pros

• Effective in decontaminating water and eliminating odors
• A reputable manufacturer behind the tablets
• Compatible with bromine, chlorine, etc
• No issue regarding chloramines buildup

Cons

• Price could have been better.
• May take time to clear very cloudy water

Renew Spa Shock is a suitable choice for anyone looking for a chlorine-free shock. You can use this shock of potassium peroxymonosulfate in many ways to keep your swimming pool clear, clean, and sanitary.

It works because of its two-step “Reserve/Renew System.” The step one is Reserve that is basically sodium bromide. You have to apply the Renew to activate the Reserve. The interaction of the two chemicals creates bromine to sanitize your pool.

You may want to opt for it if your eyes cannot tolerate chlorine. However, you can also use it with chlorine, if you want, as well as with ozone, bromine, and mineral purification systems.

If you use it without chlorine, you do not need any floater or tabs. You can also use it with chlorine to burn off ammonia and chloramines. It is available in an economical bulk package and is buffered to discourage pH fluctuations.

Verdict

Coming from a reputable manufacturer, Renew Spa Shock works reasonably well with or without chlorine. It destroys deodorants soaps, and microorganism. You may find it a bit costly though.

Dry Tec Calcium Hypochlorite Shock

Pro

• Available in a pack of 24 bags
• Quick-dissolving sanitizer
• Efficient with 68% calcium hypochlorite
• Effective against organic contaminants

Cons

• Large doses needed for desired results
• Relatively expensive

Whether you are looking for something for Intex pool or you need a way to clean your aboveground pool, try this hypochlorite shock.

Available in a pack of 24 bags, this fast-active chlorinating shock can kill bacteria in the pool. It works efficiently against algae and eliminates organic contaminants from your pool.

It uses 68% calcium hypochlorite, which is why it works quickly to improve the appearance of your pool. You may want to put your money on it if you do not like slow-dissolving chlorine tablets. It raises chlorine levels quickly because it dissolves in no time.

It promotes clarity, but you may need to use at least one bag for every 10,000 gallons of water.

Verdict:

Dry Tec Calcium Hypochlorite Shock is highly effective against bacteria and algae. It works quickly to improve the clarity and overall appearance of your pool. You need to use a lot to get good results though.

In the Swim Chlorine Pool Shock

Pros

• Highly effective chlorinated shock treatment
• Availability of 68% of calcium hypochlorite for better results
• A quick chlorine boost for proper sanitation
• Suitable for pools sanitized with bromine

Cons              

• Only larger doses improve chlorine levels
• Cannot save the unused bag

When you are not that interested in chlorine tablets, using chlorine shock may serve you well. This highly effective shock treatment from In the Swim offers fast-acting oxidation. It proves efficient because of 68% of calcium hypochlorite.

It is effective against algae buildup and de-contaminate at the same time. You can use the shock treatment for your pools sanitized with bromine. You can enjoy swimming soon after treating the water with the product.

You get 24 bags, so using it is highly convenient. Just keep in mind that you cannot save the bag and have to use the entire content once opened.

The recommended dosage is 1 pound for every 10,000 gallons. However, you may have to use more to increase chlorine percentage to the required levels.

Verdict

In the Swim Chlorine works efficiently to remove bacteria and eliminate dead chlorine cells. It may take time to improve chlorine levels in the pool though.

Swim Best Chlorine Tablets

Pros

• 3-inch commercial grade tablets
• Individually wrapped for easy handling
• Up to 90% stabilized chlorine
• Slow-dissolving chlorine tabs

Cons

• May take a long time to dissolve completely
• May make your eyes burn a little

If you like chlorine tabs that take time to dissolve, try Swim Best tablets. You will not find tabs that take longer than these tablets to dissolve in the water. The longer they take to dissolve, the higher the chances of you having chlorine available in the pool.

These tablets are individually wrapped, so you can use them quite easily. They are available in a 25-pound bucket. It is possible to use them in skimmers, feeders, and floaters after unwrapping them. They are highly concentrated with 99% trichloro-S-triazinetrione. They are also stabilized to protect chlorine from the sun.

They are efficient and quite popular, but the downside is that they may take a little too long to dissolve. In most cases, people want it to dissolve in 8-12 hour filter run. These tabs can take a couple of days to dissolve completely. The upside is that you may have to use only 2-3 tablets a month.

Another issue is about having irritated eyes if you swim for long after treating the water. Nevertheless, they are quite efficient, easy to use, and somewhat affordable too.

Verdict:

Opting for these Swim Best tablets is a good investment because they are quite powerful. You need only 2-3 of these individually wrapped tablets a month. Be prepared to wait for long to see them dissolved completely.

In the Swim Concentrated Tabs

Pros

• Quite powerful with 90% stabilized chlorine
• Possible to use in the automated chlorinator
• Individually wrapped tablets
• Slow dissolving tabs for improved sanitation

Cons

• May have to remove the plastic wrap to help them dissolve
• Poor customer service

In the Swim Concentrated tabs are among the slowest-dissolving chlorine tablets available for your pool.  You can use them in hot tubs as well, but they are more suitable for smaller pools. They are available in a 25lb bucket with 55 tablets per bucket.

They are quite powerful with 90% stabilized chlorine. Each pill contains 99% Trichloro-S-triazinetrione for maximum performance. You can use the tablets in a floating dispenser or automated chlorinator, which makes them quite easy to use. They are also suitable for skimmers and feeders.

They take their time to dissolve when used in dispensers though. The tablets are also thicker as compared to other chlorine tablets. That is why they are the slowest-dissolving tablets available for your pool. You can get good results simply by using 1-2 tabs for every 10,000 gallons of water every week. While the product is effective, the customer service is a mess.

Verdict:

A highly impressive product in terms of quality, but not backed by good customer support and affordable price.

What are Chlorine Tablets

Just as the name suggests, these are tablets that contain chlorine and other chemicals. This mix of chemicals acts as a disinfectant for your pool and kills the germs and other impurities.

Any impurities in the water can not only make your pool look dirty, but also pose a threat to the health of your family and anybody who may get into the pool. The chlorine tablets gradually release chemicals into the water and eliminate these unwanted bacteria and viruses.

How Much Chlorine Should You Use?

This can be a trick question depending on the size of your pool, how much debris you get, and the type of your pool (i.e., indoor vs. outdoor, in-ground vs. above ground).

Normally, the right number of chlorine tablets depends on the number of gallons of water in your pool. As a rule of thumb, it is ideal to add one tablet for every 5000 gallons.

One thing you need to make sure is to round off the number of gallons to the next 5000. For example, if your pool contains 15,000 gallons of water, consider adding 3 tablets. Likewise, if your pool is 20000 gallons, you will need to add four tablets. If your pool is 16000 gallons, you need to add four tablets.

What is the Best Time for Chlorination?

Most experts agree that chlorination should be done in the evening or at night. The simple reason is that chlorine will have more time to work and kill the bacteria and viruses in the absence of sun.

Fair enough, the stabilized chlorine can offer some shield against the harsh sun rays, but it does not block them completely. This is why it’s ideal to add your chlorine tablets to the pool at night. However, in case you have an indoor pool, you can chlorinate any time of the day.

Chlorine safety and precautions

Since chlorine tablets contain an assortment of chemicals, due diligence is required for proper storage and usage.

Store the tablets in a cool, dry and ventilated place. Remember, exposure of chlorine to bleach or even liquid chlorine can result in the release of harmful gases, even explosion. Likewise, contact with moisture or dirt can minimize the potency of chlorine tablets.

As long as you can make sure that chlorine tablets are properly packed and stored, they don’t pose any harm. Here are a few things to keep in mind for further safety:

• Store out of reach of children and pets
• Chlorine can be poisonous, so don’t ingest chlorine tablets
• If you see chlorine fumes coming out of tablets, take them outdoors and avoid inhaling the fumes
• Use gloves to touch any type of chlorine
• Don’t mix with any other chemicals
• Don’t mix with other types of chlorine

Why You Should Not Add Chlorine Tablets to the Skimmer?

Some people might suggest putting the chlorine tablets in the skimmer for easy chlorination.

Simple solution right?

Well, maybe not!

Pool pump and filter are the two main organs of your pool’s circulation system. If you put the tablets in your skimmer, once you turn the pump and filter off, the tablets will gradually start dissolving into your skimmer.

This can form highly acidic water which can go into your filter when you turn the pump back on and damage the internal parts of the filter such as cartridges, O-rings, and gaskets.

What’s the best way to chlorinate your pool then?

Instead of using the skimmer, consider getting a chlorinator, which can run on a preset setting to gradually release chlorine into your pool.

A chlorinator usually works with your existing pump and filter and can be installed pretty easily. The best thing about using an automatic chlorinator is that it will ensure even distribution of chlorine across the entire body of water.

The only downside is that it can be a little expensive.

However, if you don’t want to invest too much money, you can get a floating chlorinator. It is just a plastic vessel that keeps floating in the pool and releases chlorine into the water.

Not as effective as a chlorinator, the floating chlorinators are extremely cheap and can be found at your local stores.

If you don’t want to spend any money at all, you can just drop the tablets into your pool water directly. Just make sure that you drop them next to the point of water return. This can avoid any damage to your pool’s circulation equipment.

Final Thoughts

The best chlorine tablets will keep your pool water crystal clear without shrinking your bank. The tablets on our top 10 list are not only highly effective but are also long-lasting. Furthermore, there are many other ways they make your life easy.

Firstly, you don’t have to chlorinate too often. Secondly, they work pretty fast to eliminate the bacteria, viruses, pathogens, scum, slime, and other germs. What’s more, most of the above-mentioned products are very safe and come in conveniently sized packages.

In short, these tablets will keep your pool clean and safe at an affordable price and with little effort.

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