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Trichlor Chlorine: Should You Use It in Your Pool?

Trichlor Chlorine: Should You Use It in Your Pool?
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When it comes to pool care, you should know how to maintain your pool’s chemical balance. Whether you maintain or own a pool, a slight mistake like mixing different products in the wrong proportions or putting an excessive amount in your pool can have significant consequences.

For many pool owners, knowing the right product to use can be hectic. It can be difficult to find one that you can rely on among the many chlorine forms available in the market and pool supply stores.

With Trichlor, you do not have to worry about that. It has already been mixed and comes in tablet form. According to the CDC, knowing the suitable chlorine can help you prevent recreational illnesses from water and protect you and your family.

Let’s take a closer look at Trichlor, a popular pool sanitizer, why it’s ideal for daily chlorination, any downside that it might have. 

What Is Trichlor?

Trichlor is a type of chlorine commonly used in swimming pools and spas. Its full name is Trichloro-S-Triazinetrione. The product contains 90% of chlorine, a dry solid in the form of a tablet. It is equivalent to 0.9 pounds of chlorine gas. It has the highest level of chlorine among other pool sanitizers, except for gaseous chlorine, which is not used in residential pools.

Who wants to treat their pool every few hours or days, even without regular use? This product comes from a mixture of cyanuric acid and chlorine. A blend that is not only safe but also guarantees longevity.

If you are worried about those nasty skin conditions brought about by a dirty pool, then you will love what Trichlor chlorine tablets can do. Its main function is to eliminate disease-causing organisms like algae, bacteria, viruses, and parasites in hot tubs and pools so that you can enjoy your pool and hot tub like a boss!

Trichlor is highly efficient in killing germs that have a way of turning up in the water. The substance is also soluble in water, forming hypochlorous acid and hypochlorite ions or free chlorine.

Swim Best Trichlor 3 inch Tablets, 50 lbs
  • Eliminate bacteria, algae, and other organic contaminants, keeping your pool clean and clear all season long.
  • 99% Trichloro-S-Triazinetrione and 90% available stabilized chlorine.
  • Dissolve slower helping you to avoid inconsistent chlorination.

How Does Trichlor Work?

Once you release Trichlor products in the spa or pool water, it dissolves to form hydrochloric acid that combines with the contaminants and destroys their cell walls. Hydrochloric acid is highly corrosive and disrupts its chemical structures.

When this happens, the microorganisms are unable to multiply or contaminate their surroundings with bacteria and diseases. Hence the water becomes free from germs that can cause diseases. Trichlor does a better job compared to others due to its high chlorine concentration.

Note, for every 10 ppm free chlorine added by Trichlor, it increases Cyanuric acid levels by 6 ppm. Since Cyanuric acid doesn’t degrade, it’s essential to keep checking its level throughout the pool season to prevent raising to high toxic levels.

How to Use a Trichlor

The amount of Trichlor to be used for daily chlorination in your spa or pool depends on the volume of the water and several pool water parameters, including pH and calcium hardness. However, an average of 4 to 16 pounds of it is sufficient per 10,000 gallons of water.

Using a dispenser or automatic chlorinator with the right flow control mechanism ensures that the proper amount of free chlorine is added. And since Trichlor tablets are about half Cyanuric acid, they will continue to raise your Cyanuric acid level over time.

There are instructions on the EPA registered product that help apply the Trichlor for different purposes. Also, the application method depends on the form of the product. Another way is by monitoring the combined chlorine with a pool test kit.

You can also determine how much Trichlor you need by checking out the size of your swimming pool. The larger it is, the more chlorine you will have to add. A larger dosage of chlorine is required for pools made from concrete or pebble. However, you should note that Trichlor products are toxic when mishandled.

Floating Chlorine Tablet Dispenser
  • CAPACITY: Holds up to 5 chlorine tablet sizes up to 3” (tablets not included)
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Safe Use

Before you add Trichlor:

  • Ensure you read the label carefully.
  • Take note of the safety rules before you start to use them.
  • Read them and follow them if you do not want to end up with some severe injury or harm your health in any way.

Pregnant women, people under 18 years of age, and people on some other medication should first consult their doctor before using these slow dissolving cal hypo tablets. Trichlor might cause some kind of irritation when used on moist skin. So, avoid touching it with bare hands or face after applying it to the pool water.

Inhaling trichlor vapors in an enclosed space can cause severe respiratory irritation. So, make sure that you do not use it in such places and only contain the vapors within the boundaries of your pool.

You must wear rubber gloves while using the product. Also, eye goggles are necessary to protect your eyes against its strong fumes or splashing them on the eyes. Wash your hands and face with fresh water after applying it.

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To handle Trichlor granules or tablets for pool water, you need to be knowledgeable and trained to safely handle and use them. The product label contains safety information and its proper application.

You should not mix Trichlor with other chemicals used in the pool. Doing so could pose a health risk. So, never use it with any other treatment products or ingredients since this can result in chemical reactions that may be harmful to you.

Such reactions are even riskier if the pool has been recently treated for algae control and has high chlorine content. Trichlor should be stored in a ventilated area that is cool and not contaminated and also where there are no materials that can be easily oxidized since it has strong oxidizing properties.

When to Use

Trichlor pool treatment is best when used every day. The dosage depends on the size of your pool. A normal-sized swimming pool should have one Trichlor tablet dissolved in 5000 gallons of water at least once a week. Excessive usage can stain your pool surfaces and equipment.

If your initial dose fails to clear up the algae, then you should use it twice a week until the problem is under control. You can use it daily to speed up the process of getting rid of algae. The Trichlor tablets are designed to dissolve slowly so that they do not splash around when dropped in the water.

You can drip-feed using an automatic chlorinator or dispenser. An automatic chlorinator is also the best way to add chlorine to your pool. Since it helps them dissolve slower and more evenly, which reduces the risk of splashes, it also provides accurate dosage.

So, you can safely use it along with any other products without compromising their efficiency. You can find the safety precautions on the product label, so make sure you read them before using the product.

HTH Trichlor Chlorinating Granules, 50 lbs
78 Reviews
HTH Trichlor Chlorinating Granules, 50 lbs
  • BENEFITS: Sanitize, clarify, and soften the water in your swimming pool so it is always ready for fun
  • USE: Apply directly to pool water, broadcasting it evenly over a wide area in the deepest part of the pool. Add granules while filter pump is running during the evening. Use clean, dry scoop only used for...
  • COMPATIBILITY: Chlorine and saltwater systems

When Not to Use

You should not use Trichlor in an outdoor pool since it can be blown away by the wind. In addition, the strong oxidizing property of this product means that it might even destroy other chemicals like liquid chlorine, so you must avoid using it simultaneously with any other pool disinfectant or algaecide.

Thoroughly clean your pool before you start using this product. If any other treatments are used in the pool, wait for at least 24 hours before adding Trichlor. The best results are achieved when it is followed by algaecide application or shock treatment.

You must also maintain your pH level to eliminate algae that always occurs from the pH level being too low. As a result of your pH level being too high or too low, algae will develop as they thrive in such conditions.

So, you must keep an eye on your pool’s pH levels and ensure that it falls between the 7.2 to 7.8 range. It is best not to use this product if the pool has a plaster lining since it might damage it. It is also not recommended for vinyl pools and spas.

Pros of Using Trichlor

Some of the benefits of using Trichlor include:

  • Trichlor chlorine tablets are affordable compared to other sanitizers.
  • Strong chlorine concentration makes it more effective when killing germs and algae.
  • Easy to use. You can simply drop the tablet in your pool and get rid of algae.
  • Designed to slow-dissolve. As a result, it won’t splash water everywhere, and users won’t be bothered by the odor. Additionally, the slow dissolving characteristic makes it spread evenly in the pool.
  • It does not affect your pool water’s pH level or chlorine levels, which allows you to use it safely with other pool sanitizer products like algaecide or shock treatment without compromising their efficiency.
  • Lasts longer than bleach. It gives you more value for your money since you only need to use small quantities of it at a time.
  • A long shelf life compared to liquid chlorine.

Cons of Using Trichlor

  • Toxic to aquatic life and may cause damage to pool users and pets if they come into contact with it.
  • Must be used with care. For at least 40 minutes after the treatment, you should leave the room whenever you use it and do not return to the pool.
  • Using too much Trichlor can stain or rust your pool surfaces. Therefore, you must carefully measure the dosage before every use to prevent overuse.
  • It’s a volatile substance that is potentially explosive if mixed with Cal-hypo.

Alternatives to Using Trichlor

There are various types of sanitizers that you can use for your pool. Most of these sanitizers are readily available, safe to use, and affordable. Here are a few alternatives of the chlorine products that you may want to consider instead of Trichlor chlorine tablets:


Dichlor or Dichlor-S-Triazinetrione is the other chlorine product that you can buy that contains its own appropriately measured dose of CYA (cyanuric acid). Dichlor contains an average amount of about 55-62% of chlorine. It is in the form of granular and tablet, which means it is easy to handle. This product eliminates pathogens, viruses, and parasites in your pool, just like calcium hypochlorite.

Dichlor’s granular form dissolves easily in water making the sanitizing process comfortable since there are no chemical odors or irritants. It also doesn’t damage your pool lining if it is vinyl or plaster. People prefer to use Dichlor for their home pools since it is a little milder compared to Trichlor.

Sodium Hypochlorite

Sodium hypochlorite needs the addition of Cyanuric acid as it is an unstable form of chlorine and contains about 10% of chlorine. It works by killing algae and pathogens in your pool, just like calcium hypochlorite (Cal Hypo). Sodium hypochlorite, also known as liquid chlorine, comes in liquid form.

Calcium Hypochlorite

Calcium Hypochlorite is one of the available chlorine products. It contains about 40-80% of available chlorine and comes in granular form and tablet form at times. It can be primarily used as a pool shock and is also found in other sanitizing products.

Lithium Hypochlorite

Lithium Hypochlorite contains 35% of free chlorine, and it is a granular sanitizer. It is a great shock because it dissolves quickly in water, but it is not as strong as others and is expensive compared to the others.

Trichlor FAQ

What Is Trichlor Used For?

Trichlor is used to eliminate bacteria, algae, and parasites in your swimming pool. It has a pH value of 3, so it slightly lowers the pH of your pool. It comes in tablet form that dissolves slowly and evenly in water. You should dissolve it in a plastic or glass container that is non-metallic before adding it to your pool.

Is Trichlor Chlorine?

Trichlor is chlorine that contains about 90% of pool chlorine, so you can use it to sanitize your pool. Trichlor tablets dissolve slowly and evenly in water.

What Is the Difference Between Dichlor and Trichlor?

Both are chlorines, but Trichlor tablets dissolve slowly, whereas Dichlor dissolves quickly. Trichlor contains about 90% of available chlorine, is mixed with cyanuric acid to stabilize it, and comes in tablet form. Dichlor contains an average amount of about 55-62% of available chlorine. It is in the form of granular and tablet. It is also unstable, and you can add CYA, but you have to measure it carefully.

Why Is There a Trichlor Shortage?

The shortage of Trichlor is because its main ingredients, trichloroisocyanuric acid, and trichloroacetic acid, are limited. Plastic and pesticide production uses both. The production has decreased since 2008, and this has led to a decrease in Trichlor supplies.

Use Trichlor for Your Pool

Any chlorine-based sanitizer can do a good job. But the products have different costs and effectiveness. While others are easier to use than others, all that matters is the much time you are ready to invest in the various chlorine-based sanitizers.

But, Trichlor is definitely the best option due to its effectiveness, and you do not need to apply it daily. One application can take care of your pool for some time. And also, it is suitable for pool owners who do not want to proportionate or measure different chemicals.

Trichlor chlorine tablets are also a lifesaver for those with busy schedules and who have a hard time staying on top of their sanitation duties. You can simply guess out of chlorination, and that gives you time to focus on other things.

Pricing on this page was last updated on 2024-04-20