The cleanliness and safety of your pool is not up for debate, and chlorine remains a key factor in disinfecting your pool. Whether it’s to combat bacteria, algae, or cloudy water, chlorine delivers the same results every time. But with both tablet and liquid chlorine readily available, the age-old dilemma facing pool owners is: Which is better?
Introduction
Chlorine tablets, such as trichloro or calcium hypochlorite, come in a concentrated solid form, while liquid chlorine provides a quick, pour-and-use solution. Both are easy to use disinfectants, but their contrasting uses, effectiveness, and convenience may make one more suitable for your needs. In this article, we’ll delve into the pros and cons of chlorine tablets vs. liquid chlorine, including their disinfectant effectiveness, convenience, and value. By the end, you’ll feel comfortable making a final decision on whether chlorine tablets or liquid chlorine is better for your pool.
What are chlorine granules (or trichloro granules) and liquid chlorine?
Let’s start with the basics to determine which is more suitable. Chlorine tablets are solid chlorine and are most commonly dichloro (sodium dichloro-S-triazinestrione) or cal-hypo (calcium hypochlorite). Chlorine tablets, also known as trichloro tablets, are a powerful and durable form of cyanuric acid stabilized with 90% chlorine. Chlorine tablets are dissolved in water to provide long-term chlorine disinfection in swimming pools or through electrolysis treatment.
Liquid chlorine, or sodium hypochlorite chemically, is a water-based disinfectant that contains 10-12% chlorine, which is significantly higher than the 6-7% found in household bleach. Liquid chlorine is made up of chlorine, water, and a small amount of salt, so it is not stable because it does not contain CYA to prevent degradation from UV rays. You simply pour it into your swimming pool and it dissolves instantly to remove dirt.
The main difference between the two types of chlorine is that granular chlorine is a solid, usually stable, and must be dissolved, while liquid chlorine is ready-to-use, fast-acting, and unstable. This difference in efficacy and usage is the basis of this comparison.
Effectiveness: Chlorine tablets or trichloroform tablets
Chlorine tablets add strength and elasticity to water. Trichlor tablets, with chlorine levels as high as 90%, are the best choice for daily disinfection and treatment of swimming pools. Trichlor dissolves slowly when added to a chlorine generator or floating chlorine dispenser, providing a constant level to combat algae and bacteria. During the shock treatment process of a swimming pool, Cal Hypo with a chlorine level of 65% should be added in large quantities to remove organic contaminants after heavy use or heavy rain.
Pro Tip: Reliable Swimming Pool Water Treatment Scottsdale AZ services to keep your pool crystal clear, safe, and ready to enjoy. Call our experts today!
The stabilization of chlorine is an advantage. Trichlor tablets contain CYA, which protects the chlorine from sunlight, giving it a longer lifespan, making it ideal for outdoor pools exposed to direct UV rays. However, be aware that chlorine tablets have a distinct disadvantage: CYA builds up, making the chlorine ineffective at chlorine levels above 100 ppm.
Chlorine tablets or trichloroform have different effects on pool chemistry. Chlorine tablets have a low pH (around 3.0), which lowers the pool’s pH and requires alkalinity adjustments, while the high pH (12) and calcium content of calcium hypochlorite can increase hardness and pose a risk of scale formation. Despite these adjustments, the long-term effects of chlorine tablets make them a good choice for long-term pool health.
Efficacy: Liquid chlorine
Liquid chlorine has the advantage of being fast and immediate. Available in 10-12% concentration, it is less concentrated than trichloroform tablets, but it works immediately upon application. This makes it a popular treatment for shock. It quickly increases free chlorine levels to eliminate algae blooms, chloramines, or cloudiness. In a 10,000 gallon pool, 64 ounces of liquid chlorine will increase the chlorine level by 5 ppm, clearing the water in just a few hours.
However, the unstable version is a double-edged sword. Unstable liquid chlorine degrades rapidly when exposed to sunlight, perhaps 90% degraded in 13 hours, so it has little value for daily use unless a stabilizer is added (separately). A pH of 7.4 means that an acid is required to keep the pH in the range of 7.6 to 7.6.
Liquid chlorine has the properties of being fast dissolving and highly effective, but liquid chlorine has a short lifespan and is therefore not as useful for continuous disinfection as pretreated trichlor pellets. In other words, liquid chlorine is fast but lacks the durability to clean swimming pools.
How to use chlorine tablets?
Several steps must be followed to ensure successful use, promoting safety and best results when using chlorine tablets.
- Water Testing : Test chlorine (1-4 ppm), pH (7.4-7.6), and CYA (30-50 ppm) levels with a pool test kit ($20-$50).
- Dosage Calculation : For Trichlor pellets, add 1 ounce per 5,000 gallons of water, which will release 5 ppm of chlorine. Adjust dosage based on pool size and cleaning frequency (daily disinfection vs. one-time shock).
- Pre-dissolving : Mix the chlorine tablets in a bucket with the pool water, making sure the tablets are completely dissolved. This will help prevent bleaching or damage to the pool surface, especially vinyl planks.
- Apply : During the shock treatment, spread the solution evenly around the pool area.
- Brush : The brush helps to break up the fine particles.
- Wait : If shock occurs, wait 12-24 hours until the chlorine level returns to 4 ppm or below before swimming.
- Safety Precautions : Protect yourself with gloves and eye protection. Do not mix with other chemicals and store Trichlor pellets in a cool, dry place. Use properly to maximize disinfectant properties and protect your pool.
Advantages and disadvantages of chlorine tablets or trichloro tablets
Chlorine tablets have unique strengths: their stability, especially trichlor tablets, allows for a long chlorine release, reducing the frequency of use. They are readily available at pool supply stores or online, and their shelf life (up to several years) makes buying in bulk a sensible option. Chlorine tablets, such as dichlor, dissolve quickly without residue, and calcium hypochlorite provides a powerful boost to even the most aggressive contaminants.
However, where does the downside lie? Trichlor pellets are initially more expensive ($5-7 per pound, compared to $4-6 per gallon for liquid) and require some labor before dissolving. The CYA buildup of trichlor pellets requires dilution with water, while the calcium in calcium hypochlorite increases hardness and scale formation. In the case of vinyl pools, undissolved pellets will bleach when handled improperly, so they are less malleable than liquid chlorine.
Advantages and disadvantages of liquid chlorine
Liquid chlorine is also convenient because it’s inexpensive and easy to use. Just pour it in and the chlorine evaporates quickly, making it ideal for quick solutions. It also has a lower initial cost of $4-$6 per gallon and doesn’t leave any residue or scale hazards.
In contrast, its shelf life is typically limited to 4 to 6 weeks, making it unavailable for bulk purchase, and it degrades rapidly in sunlight without CYA (an additional $20-30). The larger bottles are heavy, prone to spills, and its high pH requires acidification. The lower price for repeated doses, combined with the labor required for daily inspection, can make it less convenient than trichloroform tablets.
Which is better? A detailed comparison between liquid chlorine and granular chlorine.
So, is tablet chlorine better than liquid chlorine? It depends on the application. For routine disinfection, trichlor chlorine tablets are ideal. Their slow breakdown and UV protection keep chlorine levels consistent, with maintenance reduced to just weekly checks. For a 10,000-gallon pool, you’ll need 2-3 ounces of trichlor chlorine tablets per week ($1-2) compared to 1-2 gallons of liquid chlorine per day ($4-12). Therefore, tablet chlorine is more convenient and cost-effective in the long run.
Liquid chlorine is a product that can be a shocker because it dissolves so quickly. 64 ounces of chlorine can be dissolved in a 10,000 gallon pool for $2-$3, while 2 pounds of trichloroform tablets ($10-$14) must be dissolved and allowed to dry. In this case, liquid chlorine has the advantage of being faster and cheaper to dissolve.
Pro Tip: Discover the Best Water Purification System Scottsdale AZ for fresh, pure water. Expert installation and maintenance—contact us today!
The type of pool also plays a role. Vinyl pools require liquid chlorine or dichlor pellets to prevent bleaching, while plaster pools can easily use trichlor or calcium hypochlorite pellets. In terms of cost, chlorine pellets are more cost-effective in the long run, but liquid chlorine is only suitable for temporary applications. In terms of performance, chlorine pellets provide long-lasting power, while liquid chlorine is fast-acting. Neither is always “better,” but trichlor pellets are often the more versatile.
summarize
Both liquid and granular chlorine can make a pool sparkle, but each has its own strengths that meet different needs. Trichlor granular chlorine is best for low maintenance, continuous disinfection, stability, and a lifespan that can save you months of time and money. Fast-acting liquid chlorine is effective for shock absorption and emergency use, but its short-term use and handling limitations make it problematic for everyday use. For most pool owners, trichlor granular chlorine offers a better balance between functionality and convenience, especially for outdoor pools. Alternatively, compromise solutions like daily granular chlorine treatment may be the best solution. Choose based on your pool needs and maintenance routine to ensure the safest, cleanest splash-proof water possible.