Compare Calcium and Sodium Hypochlorite

[jereece]

I normally use bleach to chlorinate my pool, but my water is very soft (almost no calcium). So, I was thinking about using Calcium Hypochlorite for a while until my calcium gets up to normal levels. I want to do a cost compairson of Sodium Hypochlorite (5.25%) and Calcium Hypochlorite (65%) but am unsure how to compare the two. The main thing I need to know is how much "available chlorine" is in each product. Since the chemical forumulas are NaOCl and CaOCl, are they one to one equivalents? In other words does 1 pound of NaOCL provide the same available chlorine as 1 pound of CaOCL? If this is the case then the conversion will be easy.

Thanks,
Jim

[duraleigh]

Hi, Jim,

I'm not smart enough to do the math but have experience using both. The cost is just about a wash.....cal hypo works out marginally more expensive based on my consumption...not enough to count.

I sure like the convenience of cal hypo but my calcium levels will approach normal about mid-summer so I'll switch back to bleach then.

[waterbear]

If you are using 65-68% cal hypo then one pound is the equivalent of 1 gallon of 10-12.5% liquid chlorine (not exact but close enough!)

Beware, much of the cal hypo out there, particularly the HTH stuff is now only 45-48% becuase Walmart had an explosion and fire from it in one of their warehouses and wanted the strength reduced! (When Walmart speaks vendors listen!) HTH is about to reformulate their shock again and include phosphonic acid, a seqesterant. This could increase the phosphate content of your water. We just had a meeting about it at work today (We carry the HTH line) and the regional Mgr. wants us to try and go exclusively to the ProTeam products which are still 68% cal hypo without any additives except for their top of the line shock which also has borax in it (not really a bad thing). Now it will just take convincing our customers who are used to HTH which costs less (but you have to use more to get the same ppm chlorine so it actually costs more to use!)

[jereece]

Assuming that NaOCL and CaOCL produce the same "available" chlorine, your estimate is about what I came out with. I calculated that it would take 1.5 gallons of 5.25% bleach to equal one pound of 65% CaOCL. I looked at the price of CaOCL on InTheSwim.com and it was $130 for 50 pounds. So using the conversion above it would take 75 gallons of bleach to have the same available chloine as 50 pounds of 65% Calcium Hypochlorite. At $1.70 a gallon it would cost $127.50 for the equivalent amount of bleach. So assuming my math is correct, it should not cost me much more to use Calcium Hypochlorite for a while.

Let me know is anyone sees a flaw in my math.

Jim

[waterbear]

The only flaw I see is that it would take closer to 2 gal (1 gal, 3 3/4 quarts) instead of 1.5 gal of 5.25% bleach to equal 1 lb of 68% cal hypo.

[halds]

This is off the main topic, but someone brought up the fact the Cal hypo exploded in a warehouse. could someone tell me what would cause this to happen. I am concnered about how I should store mine.

Hal

[waterbear]

Don't know the detail but it happened at a walmart warehouse storing HTH cal hypo.

[tcjones]

This is off the main topic, but someone brought up the fact the Cal hypo exploded in a warehouse. could someone tell me what would cause this to happen. I am concnered about how I should store mine.

Hal

I used to do emergency response to chemical spills and we once responded to a pool chemical distributor that had a huge fire.

The cause of the fire: Rain water into an open window reacted with the granular chlorine that was being improperly stored there.

Keep your cal hypo stored in a dry place.

[jereece]

I have an MSDS for CaOCL that says "A fire or explosion may result if calcium hypochlorite is mixed with other chemicals, including other pool chlorinating compounds, cyanuric acid, or pool treatment chemicals, contaminated with acids or brought into contact with any easily combustible materials such as oil, kerosene,gasoline, paint products and any other organic materials." In an emergency response class once I saw a movie where someone poured oil or diesel fuel onto some CaOCL and within a few minutes it ignited into a large fire.

[bdavis]

More on the warehouse fires from calhypo.
From the Northeast Ohio Fire Prevention Association:
"As a Class 3 oxidizer, cal hypo is generally considered to be the most dangerous of the common pool sanitizing chemicals as its presence in several fires involving big box retailers such as Sam’s Club, Lowes, and Walmart, has resulted in fires so intense that they completely overcame the sprinkler systems and in several cases led to the total destruction of the facility."

http://www.neofpa.org/Pool%20Chemicals.pdf

I'm a calhypo user myself, and use caution with handling it.

Cheers