Is Cal Hypo good for pools?

Cal hypo, also known as calcium hypochlorite, is one of the most popular pool sanitizers used for keeping swimming pools clean and safe. In the opening paragraphs, we’ll provide quick answers to some common questions about cal hypo so you can get an overview of the pros and cons of using this chemical for pool maintenance.

What is cal hypo?

Cal hypo is a dry chlorine compound containing calcium hypochlorite as the main active ingredient. When dissolved in water, it releases hypochlorous acid which acts as a sanitizer to kill germs, bacteria, algae and other contaminants in pool water.

How does cal hypo work?

Cal hypo works by oxidizing organic matter and microorganisms through the power of chlorine. When cal hypo is added to pool water, it dissociates into hypochlorous acid (HOCl) and hypochlorite ion (OCl-). These chlorine compounds destroy harmful pathogens and prevent algae growth by attacking proteins in cell walls and inhibiting enzyme activity.

What are the benefits of using cal hypo?

Some key benefits of using cal hypo for pools include:

• Strong sanitizing power – Cal hypo provides a high concentration of available chlorine to kill germs and bacteria.
• Convenience – It’s easy to apply and dissolves rapidly in water.
• Cost-effective – Cal hypo is an affordable way to sanitize pool water.
• Versatile – Can be used to shock treat or maintain residual chlorine levels.
• Long-lasting – Provides a longer-lasting chlorine residual compared to liquid bleach.

What are the downsides of cal hypo?

Potential disadvantages of cal hypo for pools include:

• Corrosive – Can degrade pool surfaces and equipment if not handled properly.
• Raise pH levels – Cal hypo has a high pH which requires monitoring and balancing.
• Cloudy water – Improper cal hypo application can cause cloudiness.
• Skin/eye irritation – Direct contact can cause burns due to its strong chlorine concentration.
• Staining – Can cause greenish stains on pool surfaces at very high chlorine levels.

How to use cal hypo safely?

Here are some tips for using cal hypo safely and effectively in pools:

• Use proper safety gear – Wear gloves, goggles and protective clothing when handling.
• Pre-dissolve – Always pre-dissolve cal hypo in a bucket before adding it to the pool.
• Add it slowly – Sprinkle cal hypo powder slowly around the edges of the pool.
• Don’t overchlorinate – Add only the recommended dose based on pool size.
• Test pH and chlorine – Check levels regularly to maintain proper balance.
• Shock at night – Shocking at night allows the chlorine time to work before swimmers get in.
• Maintain circulation – Good water flow distributes chlorine evenly.

How much cal hypo should be used?

The ideal cal hypo dosage depends on factors like pool size, existing chlorine level, and targeted chlorine level. Here are some general dosing guidelines:

• 1-3 lbs per 10,000 gallons to maintain a chlorine residual of 1-3 ppm.
• 5-10 lbs per 10,000 gallons to shock treat the pool when chlorine is too low.
• Follow manufacturer’s instructions for dosage recommendations.
• Test regularly and adjust dose based on results.

How does cal hypo affect pH?

Cal hypo increases pH as it dissociates in water. Here’s a look at how it impacts pool pH:

• The high pH of cal hypo (around 12.5) raises the overall pH level in pool water.
• Every 1 ppm increase in chlorine from cal hypo raises pH by about 0.2.
• When cal hypo is added frequently or in large doses, pH rise can be rapid.
• The optimal pool pH is 7.4-7.6. Above 7.8, chlorine becomes less effective.
• pH increasers like soda ash can counteract elevated pH from cal hypo.

Can you mix cal hypo with other chemicals?

It’s unsafe to directly mix cal hypo in its concentrated form with other pool chemicals like muriatic acid or liquid chlorine. This can generate toxic chlorine gas. Here are some guidelines on mixing cal hypo:

• Always pre-dissolve cal hypo first in a bucket before adding to pool.
• Other chemicals should be added separately to the pool.
• Diluted, fully dissolved cal hypo can be added to pool water containing other chemicals.
• In general, add cal hypo to pool water before balancing chemicals like acid.
• Never mix concentrated cal hypo with vinegars, acids, or soap.

Does cal hypo have any stabilizer?

Cal hypo does not contain any stabilizer like cyanuric acid. Here’s some information on cal hypo and stabilizer:

• Sunlight rapidly destroys chlorine in pool water without a stabilizer.
• Cyanuric acid shields chlorine from UV rays, preventing rapid dissipation.
• Pools treated with cal hypo require additional stabilizer to maintain chlorine residual.
• Ideal stabilizer level is 30-50 ppm. Too much can reduce chlorine efficacy.
• Stabilized chlorine products like trichlor contain built-in stabilizers.

Is cal hypo better than liquid chlorine?

Both cal hypo and liquid chlorine (sodium hypochlorite) effectively sanitize pools. Here’s a comparison:

Factor	Cal Hypo	Liquid Chlorine
Strength	65-70% available chlorine	10-15% available chlorine
pH Impact	Increases pH	Lowers pH slightly
Cost	More economical	Slightly more expensive
Convenience	Messy powder applications	Easier liquid applications
Stabilizer	Provides no stabilization	Contains some cyanuric acid

In summary, cal hypo provides higher available chlorine content while liquid chlorine is easier to use. Cal hypo raises pH more, but liquid chlorine costs a bit more. Many pools use both products together to utilize their combined strengths.

Can you use cal hypo in hot tubs?

Cal hypo can be used to sanitize hot tubs but requires some special considerations:

• Use no more than 2 oz dissolved cal hypo per 500 gallons of water in hot tubs.
• Hot tub chlorine dissipates faster so maintenance doses should be smaller.
• Test and adjust pH and chlorine levels frequently in hot tubs.
• Shock hot tubs only when not in use, as high chlorine can irritate skin.
• Consider dichlor or liquid chlorine for hot tubs to better control pH.

Is cal hypo better than bleach?

Cal hypo and bleach (sodium hypochlorite) are both effective chlorine-based pool sanitizers. Here’s how they compare:

Factor	Cal Hypo	Bleach
Strength	65-70% chlorine	5-10% chlorine
Application	Sprinkle around pool	Pour into water
pH Impact	Raises pH significantly	Slight increase in pH
Cost	More economical	Less economical
Safety	Irritating to skin/eyes	Moderate irritation potential

In summary, cal hypo provides a higher strength chlorine source while bleach is easier to work with. Cal hypo boosts pH more, but bleach is more widely available for purchase.

Conclusion

Cal hypo (calcium hypochlorite) is one of the most trusted and reliable pool sanitizers used today. It provides a concentrated source of chlorine to effectively destroy harmful contaminants and prevent algae growth. While some disadvantages like corrosiveness and high pH exist, cal hypo remains a cost-effective, high-powered sanitizer when used properly. Taking safety precautions like pre-dissolving, testing water frequently, and maintaining proper pH balance allows pool owners to harness the strength of cal hypo while minimizing its drawbacks. For pools and spas that get heavy usage, cal hypo is a go-to sanitizer that delivers robust chlorine to keep water clean and clear.