Trichlor in Pools: All You Need to Know

Trichlor is a stabilized, organic compound that comes in granular form or tabs. Trichlor has 90% available chlorine and more than 99% active strength. In a 1% solution, trichlor lowers the pH to a range of 2.8 to 3.5.  Trichlor, also known as trichloro-s-triazinetrione or trichloroisocyanuric acid, is a chlorine compound that provides 90% available chlorine, the highest of any chlorine compound. Trichlor is a white, slow-dissolving acidic pH chlorine compound that does not cloud the water and is used for regular chlorination but not superchlorination. The pH of trichlor ranges between 2.8 and 3.0. Trichlor has a built-in stabilizer.

What is Trichloroisocyanurate?

Trichloroisocyanurate, also known as trichlorostriazinetrione, is a chemical compound with the CAS Number 89901 and UN ID Number UN2468. Trichloroisocyanurate falls under the NFPA Storage Class I. In an area without a fire sprinkler system, the maximum allowable storage limit is 18,000 pounds. The chemical formula of trichloroisocyanurate is Cl3C3N3O3.

What are the Chemical Properties of Trichlor?

Trichlor, also known as trichloro-s-triazinetrione or trichloroisocyanuric acid, provides 90% available chlorine, the highest of any chlorine compound. Trichlor is a white, slow-dissolving acidic pH chlorine compound that doesn’t cloud the water. The pH of trichlor ranges between 2.8 and 3.0. Trichlor has a built-in stabilizer (conditioner or cyanuric acid). Trichlor reacts with water to form hypochlorous acid and cyanuric acid. Trichlor is available in tablet form. It increases total dissolved solids (TDS) level by 16 ppm per 10,000 gallons. Trichlor has a shelf life of 3 years. The chemical formula of Trichloroisocyanurate is Cl3C3N3O3.

How much Chlorine is in Tricholor?

Trichlor contains about 90% available chlorine. This means that a container of trichlor has the capacity to release an amount of chlorine equivalent to 90% of the chlorine that would be released by dissolving 100 pounds of chlorine gas in water. To calculate the actual chlorine content in a product, the given percentage of available chlorine content must be divided by 2. Therefore, 90% available chlorine trichlor is about 45% chlorine.

How is Trichlor produced?

Trichlor is produced by adding sodium hydroxide to cyanuric acid to create sodium cyanurate, then adding chlorine gas under controlled conditions to get trichloroisocyanuric acid, water, and sodium chloride. The manufacturing equation is as follows: Cyanuric acid + sodium hydroxide yields sodium cyanurate. Sodium cyanurate + chlorine gas yields trichloro-s-triazinetrione + sodium chloride.

What is the Chemical Reaction of Trichlor and Water?

Trichlor reacts with water to form hypochlorous acid and cyanuric acid. The chemical equation is: Cl3CNO + 3H2O → 3HOCl + H3CNO3

What Happens When Tricholor is Added to Water?

When trichlor is added to water, it reacts to form cyanuric acid and three hypochlorous acid molecules. This reaction involves nine steps, where each of the three chlorine molecules present in trichlor eventually forms three separate molecules of hypochlorous acid. The chemical equation for this reaction is: Cl3CNO + 3H2O → 3HOCl + H3CNO3. Trichlor contains cyanuric acid, also known as a stabilizer or conditioner, which protects the chlorine present in water from sunlight. However, high levels of cyanuric acid decelerate the rate at which chlorine eliminates bacteria and other microorganisms. Additionally, these high cyanuric acid levels require an increase in free chlorine for effective disinfection and oxidation. Trichlor is highly acidic with a pH of 2.8-3.0, and when used improperly, it damages equipment, plaster, vinyl, fiberglass, and acrylic.

Where is Trichlor used?

Trichlor is used in white and colored plaster pools with an in-line or off-line chlorinator. Trichlor, or trichloro-s-triazinetrione or trichloroisocyanuric acid, is a chlorine compound used for regular chlorination of pools. Trichlor is typically sold as a slow-release tablet and is suitable for use in floating chlorinators, erosion-type feeders, and automatic in-line or off-line chlorinators. However, trichlor is not recommended for use in vinyl liner, fiberglass, acrylic, or painted pools due to the quick build-up of CYA. This quick build-up of CYA necessitates a higher level of free chlorine in the pool water to maintain effective disinfection and oxidation. Trichlor is also used as a primary sanitizer and disinfectant, eliminating all living microorganisms and disease-causing organisms in the pool water.

How is Trichlor used?

Trichlor is used as a slow-release tablet in floating chlorinators, erosion-type feeders, and automatic in-line or off-line chlorinators. Trichlor is suitable for regular chlorination but not for superchlorination due to its slow dissolution rate. Trichlor is also used as a primary sanitizer and disinfectant, eliminating all living microorganisms and disease-causing organisms. Additionally, trichlor serves as an oxidizer and algaecide.

How to increase Chlorine in the pool with Trichlor?

To increase chlorine in the pool with trichlor, it is directly added to the pool water. Trichlor reacts with water to form cyanuric acid and three hypochlorous acid molecules. The hypochlorous acid molecules increase the chlorine level in the pool. However, it is necessary to ensure that the floater, whether it is a floating duck or dispenser, is kept distant from any metal components or skimmer intake. Trichlor tablets must never be placed in the skimmer, as their acidic properties increase the chance of dissolving metal. For a more specific dosage, a formula is used to calculate the amount of chlorine needed for the pool size and desired chlorine level. The desired increase in parts per million (ppm) of chlorine in the pool is determined first. Next, the pool’s volume in gallons is divided by 10,000. The chlorine dosage table is then consulted to find the amount of chlorine needed to increase the chlorine level by 1 ppm. The values obtained from these steps are multiplied to yield the total amount of chlorine required. It should be noted that Trichlor consists of approximately 50% cyanuric acid. Therefore, adding 10 ppm of trichlor to a pool increases the cyanuric acid level by 6 ppm. When a high amount of trichlor is used, it is possible to quickly reach 50 ppm of cyanuric acid. High levels of cyanuric acid decelerate the rate at which chlorine eliminates bacteria and other microorganisms. Also, high levels of cyanuric acid require higher levels of free chlorine for disinfection and oxidation.

Are there types of Trichlor for skimmer use?

Certain types of trichlor tablets and sticks are specifically designed for skimmer use. They contain slow-dissolving chemicals and buffers to prevent damage. However, these are also dangerous when mishandled. Regular trichlor tablets or sticks are not recommended for skimmer use.

What are the compatibility considerations for Trichloroisocyanurate?

Trichloroisocyanurate is suitable for use in white and colored plaster pools with an in-line or off-line chlorinator. Trichlor is not recommended for use in vinyl liner, fiberglass, acrylic, or painted pools due to the quick build-up of CYA, that requires a higher free chlorine level.

Does mixing Cal Hypo and Trichlor cause an explosion?

Yes, mixing cal hypo (calcium hypochlorite) and trichlor (trichloroisocyanurate) with a small amount of water increases the risk of explosion and fire. This reaction produces hydrogen and chlorine gas and a large amount of heat, enough to ignite the hydrogen gas. This phenomenon is common among pool owners during the summer months, when they unknowingly combine different types of chlorine tabs in their floating chlorinators.

What are the Benefits of Trichlor?

The benefits of trichlor include its high available chlorine content, slow-dissolving nature, and built-in stabilizer. Trichlor provides 90% available chlorine, the highest of any chlorine compound. Its slow-dissolving nature makes trichlor ideal for use in floating chlorinators, erosion-type feeders, and automatic in-line or off-line chlorinators. Trichlor also contains a built-in stabilizer (cyanuric acid), which protects the chlorine present in water from sunlight. Trichlor is primarily used as a sanitizer and disinfectant, effectively killing all living microorganisms and disease-causing organisms in pool water. Trichlor also acts as an oxidizer and algaecide. Its slow dissolving nature ensures a daily release of chlorine into the water, maintaing disinfection even in the absence of regular pool service. Furthermore, Trichlor contains cyanuric acid, also known as a stabilizer or conditioner, which protects the chlorine present in water from sunlight, extending its effectiveness. However, Trichlor is highly acidic and causes damage when used improperly.

Is Tricholor stable?

Yes, trichlor is stable. Trichlor, or trichloroisocyanurate, is a compound that contains a stabilizer and is typically sold in a slow-release tablet form. Trichlor has a shelf life of 3 years, indicating its stability over time. Furthermore, trichlor is produced by adding sodium hydroxide to cyanuric acid to create sodium cyanurate. Next, chlorine gas is added under controlled conditions to get trichloroisocyanuric acid, water, and sodium chloride. This manufacturing process also suggests its stability.

What are the risks of using Trichlor tablets?

Even pools that operate their pumps continuously have chances of encountering problems related to the acid from the tablets dissolving metal components. Moreover, placing multiple tablets in the skimmer increases the acid level. An additional risk is the potential for individuals, especially children, to easily access these dangerous tablets. Exposure to these tablets has the potential of causing permanent eye damage in 15 seconds.

How Can You Test Tricholor?

Testing methods for Trichloroisocyanurate include DPD (N,N Diethyl-1,4 Phenylenediamine Sulfate), FACTS (Free Available Chlorine Test Solution), and TMP (Taylor Monopersulfate). These methods involve the use of test kits or strips that react with the Trichlor in the water, providing an indication of its concentration. Testing must be done weekly or more often when the pool or spa is heavily used. The recommended level of Trichlor in the water is 7.5% of Cyanuric Acid (CYA), a stabilizer that protects chlorine from sunlight degradation.

How to store Tricholor?

Trichloroisocyanurate must be stored in a cool, dry, well-ventilated area. Trichlor must be kept in its original container with the cap or lid securely replaced to prevent spills and maintain chemical efficacy. The maximum storage for a nonsprinklered area is 18,000 lbs.

How is Trichlor Sold?

Trichlor is typically sold as a slow-release tablet, either 1-inch (0.5 oz. or 28 grams) or 3-inch (7 oz. or 200 grams). Trichlor is also available as an 8 oz. stick or a large 28 oz. tablet. These tablets and sticks are designed to be placed in a skimmer. The slow-release nature of trichlor makes it optimal for use in floating chlorinators, erosion-type feeders, and automatic in-line or off-line chlorinators. Trichlor is suitable for regular chlorination but not for superchlorination due to its slow dissolution rate.