Hypochlorites?

[JeffW 14]

Could someone please tell me if there is a significant difference between calcium hypochlorite and sodium hypochlorite?

[RyanH 14]

Sodium ions are completely soluble in water. Calcium ions are not easily dissolved. The result of this is when you use calcium hypochlorite as a house wash, you will notice white streaks on the windows, siding, brick, etc. unless you use hot water as a rinse. With sodium hypochlorite, it will completely wash off with cold water. I tried calcium for awhile...bought it in 50 pound buckets and mixed in barrels but stopped quickly after I realized the mess it was making. Also, the calcium hypochlorite will sludge up your mixing barrels with a clay-like material over time.

[PressurePros 249]

Both will yield the same results. Differences are

1) Price: You need approximately 30 oz of crystal Ca(OCl)2 mixed per gallon of water to yield 15% chlorine. This brings the cost to about $5.25 per gallon. NaClO with 15% chlorine is about half the price.

2) I think the Ca(OCl)2 is also a more active oxidizer than NaClO. I am not positive but from my thinking this could lead to some issues with flash rusting.

Advantages:

1) Better storage, longer shelf life for dry chemical.

2) It's more stable in aqueous solution

Disadvantages:

1) You have to mix up your solution in the field.

2) Mixing of the powder poses potential for inhalation thus respiratory protection should be utilized.

3) The powder is less soluble.

[JeffW 14]

Thanks, good detailed answers.

[Chappy 138]

Both will yield the same results.

If you are doing roofs you will not get the same result. The first tile roof I cleaned, I figured that Id save money and use calcium hyperchlorite. after two hours of spraying a very strong solution on it, and respraying each area 2-3 times, I called a friend. He came over with a tank of soduim hyperchlorite mixed at 7%, (compared to my 7-8% of CH,) and started spraying. The mildew vanished almost instantly with one coat! He ended up doing 1/2 of the roof in 2 hours, while I was still rinsing off the white residue from CH 6 hours after I started.

Needless to say, I chucked the pail and started to use Sh.

[PressurePros 249]

Thanks, Jon. I'm glad you have shared a real world application. When you say your mix was 7-8% was that of chlorine yield or a 7-8% mix of solution you had prepared? The reason I ask is that in theory, if equal amounts of chlorine are delivered to a surface mold the efficacy should be equal.

I also question because you mentioned that you used the calcium hypochlorite to save money. In researching pricing, proper mix ratios would make the NaCl cheaper.

[Chappy 138]

10.5 percent pool chlorine mixed at 7gal to 10 of water.

CH is hard to mix stronger than that, because of the solubility problem. it was quite a bit cheaper as far as cost per gallon go. but the time factor makes it much more expensive. Most times, I dont have to rinse liquid chlorine. not so with powdered CH.

[Russell Cissell 65]

Calcium Hypochlorite is the old "HTH" swimming pool chlorine. Can be delivered in a powder form. You can also find it as large pellets that look like an albino hocky puck. This form only about 46% available chlorine. It has been replaced by the chlorinated isocyanurates, which are stabilized and last much longer. The calcium salt is little used today. They have found it to be harmful to most surfaces, especially around toilets (a common old usage).

Sodium Hypochlorite cannot be made into a powder, comes as a liquid only. The Sodium Hypochlorite is standard household bleach @ 5.25%. You can also find Sodium Hypochlorite that is 12% for Laundries, Restaurants and Kitchens Cleaning Contractors . Stronger means more economical and the enduser can use less to get the job done.

Best of Luck