The table below addresses the quantities of chlorine needed to disinfect tanks and reservoirs, but it can be generalized and adapted to standard residential situations. Regular supermarket grade bleach contains 5.25% chlorine. Basic chlorine pellets used in dry pellet chlorinators are around 70% to 75% calcium hypochlorite.
Example of a practical application. To disinfect your 50 gallon hot water heater requires 1.5 cups of bleach left in the tank for two hours or 3/4 cup of bleach left overnight. For a 30 gallon tank, cut the amount in half. Keep in mind that a bit too much usually doesn't hurt anything. A plumber we know regularly uses a gallon of bleach for a standard hot water heater.
|
AMOUNT OF CHLORINE NECESSARY FOR DOSAGE AND TIME COMBINATIONS |
||||||
|---|---|---|---|---|---|---|
|
Volume of Box, Basin, Reservoir or Cistern |
5.25% Sodium Hypochlorite (Bleach) |
65% Calcium Hypochlorite |
||||
|
100 ppm* for 2 hours |
50 ppm* for 8 hours |
25 ppm* for 24 hours |
100 ppm* for 2 hours |
50 ppm* for 8 hours |
25 ppm* for 24 hours |
|
|
50 gal |
1½ cups |
3/4 cup
|
3/8 cup |
- - |
- - |
- - |
|
100 gal |
3 cups |
1½ |
3/4 cup |
- - |
- - |
- - |
|
200 gal |
6 cups |
3 cups |
1½ cups |
- - |
- - |
- - |
|
500 gal |
1 gal |
7½ cups |
3 3/4 cups |
9½ oz |
- - |
- - |
|
1,000 gal |
2 gals |
1 gal |
7½ cups |
1 lb 3 oz |
9½ oz |
- - |
|
2,000 gal |
4 gals |
2 gals |
1 gal |
2 lb 6 oz |
1 lb 3 oz |
9½ oz |
|
5,000 gal |
- - |
5 gals |
2½ gals |
6 lbs |
3 lbs |
1 lb 8 oz |
|
10,000 gal |
- - |
- - |
5 gals |
12 lbs |
6 lbs |
3 lbs |
|
20,000 gal |
- - |
- - |
- - |
24 lbs |
12 lbs |
6 lbs |
|
50,000 gal |
- - |
- - |
- - |
60 lbs |
30 lbs |
15 lbs |
|
100,000 gal |
- - |
- - |
- - |
120 lbs |
60 lbs |
30 lbs |
* ppm = parts per million
(whole house & well units)