To disinfect a 700,000-gallon tank with 50 mg/l of chlorine, how much 65% HTH will be needed?

To determine how much 65% HTH (calcium hypochlorite) is needed to disinfect a 700,000-gallon tank with a desired chlorine concentration of 50 mg/l, you first need to calculate the total amount of chlorine required in pounds.

1. Convert the desired chlorine concentration from mg/l to lbs. Since 1 mg/l equals 1 pound per million gallons:

• 50 mg/l * 700,000 gallons = 35,000 mg or 35 lbs of chlorine required.

2. Determine the actual chlorine contribution from HTH. Since HTH is a 65% chlorine product, you need to find out how much HTH will provide 35 lbs of chlorine:

• If HTH is 65% active chlorine, then to find the amount of HTH required to get 35 lbs of chlorine, use the formula:

• Amount of HTH = Amount of chlorine needed / (percentage of chlorine in HTH).

• Therefore: 35 lbs / 0.65 = 53.85 lbs of HTH.

3. Convert HTH amount to pounds for the context of the question. This step ensures you're clearly linking the calculated