You can easily shock your well by adding plain unscented household bleach with a chlorine concentration of 5 to 5.25%. The amount of household bleach used varies with the type of well you have. Add 1 litre (1 quart) of household bleach for every 1.5 metres (5 feet) of depth of water.

Mix up a solution of 1/2 gallon chlorine bleach to 5 gallons water in a bucket. Scrub the well cap and the casing with a brush. Fill a clean bucket with 3 gallons water to shock a drilled well. Carefully pour 1/2 gallon of household bleach into the water.

Determine how much bleach to use, then pour the bleach down the well and circulate it through the whole water distribution system. Wait 6-12 hours for the chlorine to work, then flush the chlorinated water from your well and pipes. Retest the water after 2-3 days.