Chlorine is the pool cleanliness savior for millions of pools. However, sometimes the pool’s chlorine doesn’t clean and sanitize the pool water effectively which is known as chlorine lock.
Chlorine lock can leave your pool cloudy, unpleasant to swim in, and even unhealthy. But the good news is that with a proper pool cleaning routine, you can fix the chlorine lock issue.
This blog covers the causes and signs of a pool lock and how to block a chlorine lock with Cal Hypo. It also explores other methods to treat and prevent the pool lock issue in the future.
Let’s delve into your expert chlorine lock pool guide!
What is a chlorine lock or chlorine demand?
Though the right terminology is chlorine demand, the ineffectiveness of pool chlorine is referred to as chlorine lock. Chlorine lock is a condition when the pool chlorine loses its sanitization and shocking capacity.
During this condition, pool chlorine combines with other elements (like ammonia from sweat) to form chloramines, which are less effective at sanitizing.
What causes chlorine lock?
Here are the leading causes of chlorine locks in the pool.
- Lack of maintenance and cleaning
- Adding too much cyanuric acid or pool stabilizer
- Unbalanced pool pH
- Pool contaminants such as dust, leaves, and other debris.
What are the signs of a chlorine lock?
Proper pool maintenance and cleaning are necessary to maintain your chlorine levels in optimal balance. Otherwise, the free chlorine level (effective chlorine) may decrease and result in a reduced sanitation power.
The following are the most prominent signs of a pool chlorine lock:
Cloudy or Greenish Water
The greenish or cloudy pool water indicates algae growth in the pool. The presence of algae is a sign that your chlorine isn’t working correctly.
Also learn, Green Pool Problems: How to Clean a Green Pool Fast.
Strong Chlorine Odor
The pool’s strong and pungent chlorine smell indicates a higher concentration of chloramines, which is a sign of the pool lock.
Skin or Eye Irritation
A pool with super chlorine levels will irritate the swimmers’ eyes, ears, or skin.
Unbalanced Chlorine Levels
Another way to identify the pool chlorine lock is to test your pool’s free and total chlorine levels. If the free and total chlorine levels are unequal, you may have a chlorine lock because these numbers remain the same under normal conditions.
What is a Cal Hypo?
Cal Hypo, or calcium hypochlorite, is an excellent way to raise chlorine levels. It breaks down the over-stabilized chlorine more quickly and makes it more effective for sanitation.
Cal-Hypo Shock Dosage for Chlorine Lock
Here are general dosage guidelines for treating chlorine lock with Cal Hypo.
Mild Chlorine Lock
Start with 1-2 lbs of Cal Hypo per 10,000 gallons of water for mild cases.
Moderate Chlorine Lock
Use 2-3 lbs of Cal Hypo per 10,000 gallons of water in moderate chlorine lock conditions.
Severe Chlorine Lock
In severe cases, you might need 3-4 lbs of cal hypo per 10,000 gallons of water.
Important Note: Always refer to the manufacturer’s instructions on the Cal Hypo product you use for specific dosage recommendations.
How do you apply Cal Hypo to your locked chlorine pool?
There are two methods for applying Cal Hypo to your lock chlorine pool condition.
Broadcast Method
With this method, slowly broadcast the Cal Hypo granules evenly over the pool surface. Walk around the perimeter to ensure even distribution of the chemicals and keep the pool filter running.
Sock or Feeder Method
The sock or feeder method ensures a slower and more controlled release of the Cal Hypo. You can place the Cal Hypo in a sock for chlorine tablets or a pool chemical feeder.
What are some other ways to treat a chlorine lock pool?
The chlorine shock treatment ensures the swimmers’ health, watercolor, and pool smell. Here are some other methods to treat a chlorine lock pool.
- Partially Drain the Pool
- Adding a Chlorine Neutralizer
- Use a Chemical Additive
1. Partially Drain the Pool
To decrease the levels of over-accumulated cyanuric acid, partially drain the pool using a submersible pump and refill it with fresh water. This process will lower the concentration of cyanuric acid in the pool.
2. Adding a Chlorine Neutralizer
Sometimes, a pool lock may result from high pH levels. To treat this condition and raise the pH levels, a chlorine stabilizer is added to the pool. The chlorine then reacts to form a new compound. Eventually, the locked chlorine is unlocked.
3. Use a Chemical Additive
Some chemical additives, such as sodium thiosulfate, ascorbic acid, and potassium permanganate, can unlock the stabilized chlorine. Here are the usage conditions for these chemicals:
- Sodium thiosulfate: add it when the chlorine lock is due to high pH levels.
- Ascorbic Acid is added when chlorine lock occurs due to over-accumulation of cyanuric acid.
- Potassium permanganate: add it when the chlorine locks due to the pool’s high organic matter levels.
What are the cons of chlorine lock?
Here are some downsides of pool chlorine lock:
Increased Algae Growth: Ineffective chlorine leads to algae buildup.
Cloudy Water: Chlorine lock can cause cloudy and unappealing pool water.
Higher Maintenance Costs: Requires more chemicals and frequent testing to correct.
Health Risks: Insufficient chlorine can lead to bacteria growth, posing health risks.
Ineffective Sanitization: Pool water may not be properly sanitized, reducing swimmer safety.
How do I prevent chlorine locks in the future?
Follow the tips below to prevent your pool’s chlorine from locking.
- Maintain proper amount of chlorine in your pool water
- Use a cyanuric acid stabilizer. The recommended range for cyanuric acid is between 30 ppm and 70 ppm.
- Maintain your pH levels in the standard and optimal range (between 7.2 and 7.8).
- Use chlorine-alternative sanitizers such as sodium hypochlorite or trichlor tablets.
- Shock your pool regularly.
- Invest in a pool cover.
Regular Chlorine Products vs. Cal Hypo: What’s the Difference?
For pool owners, the fundamental question is, what exactly is a Cal Hypo? Well, we have sorted it out for you. Both regular chlorine products and Cal Hypo are used for pool sanitation as they release hypochlorite ions. The main difference lies in the cyanuric acid.
Everyday chlorine products contain cyanuric acid (a stabilizer) to protect chlorine from UV sun rays. However, high levels of cyanuric acid may lead to chlorine lock.
Cal Hypo, on the other hand, doesn’t contain cyanuric acid. Because of this, adding Cal Hypo disintegrates the stabilized chlorine into free chlorine.
Can I mix Cal Hypo and Trichlor?
No. We strongly prohibit you from mixing Cal Hypo with Tricolor. Moreover, do not mix any pool chemicals. Mixing pool chemicals may lead to violent and hazardous chemical reactions.
Is Cal Hypo non-chlorine shock?
Cal Hypo is a type of chlorinated shock. It only differs from the chlorine shock due to its function.
How often do you add Cal Hypo to the pool?
We recommend adding Cal Hypo to your pool every other day or based on its needs. Please read the instructions labeled on the chemical package carefully.
What is the alternative to Cal Hypo?
Sodium dichloro-s-triazinetrione (dichloro) is a pool treatment chemical used instead of Cal Hypo.
Is Cal Hypo better than liquid chlorine?
Yes, Cal Hypo shock is better than liquid chlorine because it is safer for the swimmer’s health. Moreover, it is more economical and easier to handle than liquid bleach.
Final Thoughts
Proper pool maintenance and cleaning are required for a gleaming, clear water with an optimal chemical balance and pH level. Otherwise, pH and chemical imbalances may result, causing pool chlorine lock. Chlorine locks can be treated with chlorine pool shocks and other chemical shock treatments.
Calcium hypochlorite shock is an excellent choice for pool owners looking for swimmer-friendly chemicals within their budget. It is DIYable, but a professional pool company like Silverline Pools will do it more effectively.
Contact their seasoned team, maintain your pool chemical levels in the optimal range, and enjoy a hassle-free swimming season.
