I'd like a little help from someone that stores calcium hypochlorite for water purification , and is aware of the dangers it poses while handling it....it seems a little ridiculous that the governmental agencies can't come up with a more user friendly formula than

for high strength calcium hypochlorite... mix a stock solution of 1 heaping teaspoon in two gallons of water, then treat at a ratio of 1 part stock solutiion to 100 parts water (1:100), let stand 30min

if a heaping teaspoon is for two gallons
1/2 heaping teaspoon is for one gallon
1/4 heaping teaspoon is for 1/2 gallon
then 1/8 heaping teaspoon for one quart

I don't have a 1/8 teaspoon measure on hand, but just for grins measured out a heaping teaspoon of sugar as a calcium hypochlorite substitute, and found that by using a piece of 9mm brass, it took 8 "brass fulls" , or the casing held a volume of 1/8 "heaping" teaspoon


can someone that measures their pool chlorine with a test kit see how close you get to 3ppm (parts per million) with

one 9mm case full of calcium hypochlorite dissolved in a quart of water to make a stock solution

and since you need a final dilutiion of 1 part of stock solution to 100 parts of water to be treated...add 38mL of the stock solution to a gallon of water, let stand, and test

1 gallon water is 3.8 liters (L) or 3800 mL
38mL of the stock solution then is 1/100 of a gallon

edit... 9 teaspoons (measuring spoon not coffee spoon) is real close to 38mL

this might be of value to others, and would like to see what the chlorine concentration in parts per million is..., thank you for your consideration

I store calcium hypocholorite and I've got a dosing spoon left over from a child's prescription packaged with it.

Um, what are the dangers you speak of? My plan is to handle it only In a well-ventilated area wearing gloves.

chaosmagnet... there is an inhalation danger if the compound is finely powdered, and splash danger when in solution in addition to the danger from the gaseous chlorine that might be generated...small amounts of water to a large volume of calcium hypochlorite could pose an oxidizing reaction...good ventilation naturally...I would hate for a well meaning individual that does not normally handle pool chemicals to be injured...my hope was that a person that already stored HTH would also have a chlorine test kit, to see if my calculations were in the target range

take care

I do not regularly handle pool chemicals. The pool shock I bought for this purpose is in pea-sized granules. I figured that if I only handled it in a well-ventilated area with gloves on and didn't get splashed I'd be okay.

chaos... thanks for the response...it just seemed to me that the formulas posted for preparing the calcium hypochlorite solutions were a little awkward to use...

I've updated the instructions I have packaged with the pool shock in my kit with the aim that my wife or kids could use it in my absence:

Water Disinfection Instructions

NOTE: Disinfection will destroy harmful pathogens but will not remove chemical contamination.

A small quantity of water may be prepared more quickly by boiling. Any amount of boiling will do; it is not necessary to boil water for any length of time in order to destroy harmful pathogens.

1) Filter the water. If the water is cloudy or has any suspended particles in it, filter it to remove as much cloudiness/particles as possible. Use a shirt, handkerchief, filter mask, or other field-expedient means if you don’t have a purpose-made water filter. Alternatively, allow the water to stand undisturbed so that the particulate matter settles – this could be as long as 24 hours. Then draw the clear water from the top. If this isn’t possible, move on to the next step.

2) Make a stock of chlorine solution. Dissolve one heaping teaspoon (about ¾ ounce or 22ml) of calcium hypochlorite granules into two gallons (eight liters) of water. HANDLE CALCIUM HYPOCHLORITE WITH GLOVES ON AND IN A WELL VENTILATED AREA. DO NOT DRINK THE CHLORINE SOLUTION. DO NOT ALLOW THE CHLORINE SOLUTION TO SPLASH ON YOU OR YOUR CLOTHES. Store unused chlorine solution in a tightly closed container.

3) Add chlorine solution to water. Add one part of the chlorine solution to 100 parts clear water to be treated. For example, add 6.4 ounces (189ml) of chlorine solution for five gallons (640 ounces) of water. Double the amount of chlorine solution for cloudy or colored water.

4) Agitate. Loosen the cap of the container and shake vigorously, allowing chlorine solution to mix thoroughly with the water to be treated, and allowing the water to splash onto the threads of the container and the cap so that no untreated water comes into contact with people, clean containers or treated water.

5) Let it sit. Let the treated water sit for at least thirty minutes with the cap on before drinking. Increase contact time if the water is cold, cloudy, or has high pH (alkalinity). When in doubt, double the contact time.

6) Check for chlorine odor. The water should have a slight chlorine odor; if not, repeat the dosage and allow the water to stand for an additional fifteen minutes.

7) Aerate (optional). If the treated water has too strong a chlorine taste, aerate by allowing the water to stand exposed to air for a few hours, or by pouring it from one clean container to another several times.

8) Drink.

thanks for posting... just printed it...page 3 of 4

I've never dealt with pool chemicals, so this is just an educated guess.

Bleach, i.e. sodium hypochlorite, will rapidly degrade once you dilute it in water. Hypochlorite ions from calcium hypochlorite may or may not degrade as fast when diluted. But if it does, then most of that 2 gallon stock solution may lose its potency before you can use it up.

If you've never used this technique before, I'm really curious about the results, if you could do a test some day. Mix up your stock solution and store it for a couple weeks. Then add it to water according to your directions and see if it satisfies the sniff test. I suspect that even repeated applications may not ultimately pass the sniff test because there aren't enough hypochlorite ions left.

It would be great if it does work, though.

Bottled bleach can last significantly longer than a few weeks hen stored in an airtight container. Supposedly the chlorine solution instructions I found and adapted above will give you something approximating bottled bleach. I haven't tried it though. I have a number of tried-and-true disinfection methods available. This one is meant to be last ditch, or for very large quantities of water, or to disinfect a large amount of surfaces.

In other words, it's not too heavy, bulky, or expensive to include in my big kit.

That's true of bottled bleach, but this stock solution is not the same thing as bottled bleach. "Straight" bleach is highly alkaline due to the addition of sodium hydroxide. This high pH favors a form of stable form of hypochlorite.

However, once you dilute it with water (like this stock solution), the reactive form predominates and it very quickly breaks down. I'm assuming that calcium hypochlorite will react similarly to sodium hypochlorite found in household bleach.

Diluted bleach solutions are often used in labs as a cheap sanitizer, but any lab SOP will mention that this solution should be thrown out and a fresh batch made if it is older than 12-24 hours old due to loss of sanitizing potency.