Calcium hypochlorite pellets are probably the most commonly used form of chlorine in public swimming pools, but they are rarely used in private pools. Shock chlorine granules which are exactly the same chemical (calcium hypochlorite granules) are the standard treatment chemical used for boosting the chlorine level to prevent algae etc with a fortnightly treatment.
Calcium hypochlorite pellets can be used to boost the chlorine level when the pool appears to be losing clarity or algae appears in the corners or in dead spots.
How to use calcium hypochlorite pellets to boost the chlorine level
Calcium hypochlorite pellets have the same amount of chlorine in them as shock granules (70%) so you need to use the same weight of pellets as you would granules. That is for a routine fortnightly shock treatment 500 grams per 10,000 gallons (45 cubic metres) of pool water. (500 grams is 60 pellets)
The pellets should be dosed through the skimmer. They will take about half an hour to dissolve. First make sure there are no stabilised chlorine tablets in the skimmer (as stabilised and un-stabilised chlorine react violently when mixed as solids). Then add the required dose of pellets into the skimmer. Leave the circulation on at least until they are dissolved.
Easy to handle
Less dusty than granules
Because they dissolve gradually in the skimmer they give a more even distribution of chlorine through the pool.
Do not increase stabiliser level.
In a pool which has too high a stabiliser level they can be used instead of stabilised chlorine tablets or granules to allow the stabiliser level to gradually drop.