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Power Powder Plus 73 is our strongest chlorine pool shock with 73% Calcium Hypochlorite killing bacteria, algae, and contaminants for clear, sanitized pool water.

  • Kills bacteria, controls algae, and destroys organic contaminants
  • Concentrated chlorinating granular Cal-Hypo pool shock
  • Fast dissolving
  • Low Residue
  • 73% Calcium Hypochlorite
  • 70% Minimum Available Chlorine
  • Fast acting solution for swimming pool problems
  • Great for super chlorination and routine maintenance use
  • Non-Stabilized – No Cyanuric Acid (CyA)
  • 9-18 oz. per 10,000 gallons provides 5-10 ppm available chlorine


When you have an algae bloom or need to treat other pool problems, look no further than Power Powder Plus 73 Cal-Hypo Pool Shock. With 73% Calcium Hypochlorite active ingredient and a minimum of 70% available chlorine, it’s the strongest pool shock available. Power Powder Plus 73 is known as a solution shock as it destroys algae blooms and organic as well as inorganic contaminants. Power Powder Plus 73 Calcium Hypochlorite Pool Shock is also great for weekly maintenance to super chlorinate and give your chlorine levels a quick boost when you need it. Whether you’re using Power Powder Plus 73 as a treatment or maintenance pool shock, it’s extremely effective at keeping pool water sanitized and safe for swimming.

Active Ingredient: 73% Calcium Hypochlorite

Power Powder Plus 73 Pool Shock has the highest percentage of Calcium Hypochlorite available for a super strength and concentrated pool shock. Some other pool shocks have a lower percentage of active ingredient with a higher percentage of inert ingredients which reduce the amount of chlorine sanitizer that is ultimately added to your pool.

70% Minimum Available Chlorine

With Power Powder Plus 73, you get at least 70% available chlorine to kill and inactivate algae spores, bacteria, germs, and other water contaminants. Don’t settle for anything less when looking for a pool shock to effectively treat pool problems like algae blooms and swimming accidents fast. As the chlorine dissolves in the water, it forms hypochlorous acid which is what kills and eradicates algae and bacteria.

Low Residue & Fast Dissolving

Fast acting and dissolving, Power Powder Plus 73 works quickly to kill algae and bacteria without leaving any noticeable residue behind. Even though it is a calcium based granular chlorinated shock, it won’t significantly increase calcium hardness levels in the pool water. Power Powder Plus 73 Calcium Hypochlorite shock works fast to eliminate contaminants currently in the water while preventing future potential algae growth.


Please Note: Depending on water chemistry levels such as high pH and Calcium Hardness, Cal-Hypo shock can cause possible turbidity or clouding of the water when added. This will normally clear up on its own.

Non-Stabilized Chlorine Pool Shock

There is no stabilizer or conditioner in Power Powder Plus 73 Cal-Hypo Pool Shock so adding it will not raise cyanuric acid (CyA) levels in the pool water if they are already elevated. With this in mind, it’s best to add during evening hours while the filter pump is running to reduce UV degradation from the sun.

Power Powder Plus 73 Cal-Hypo Pool Shock

To get rid of the toughest of algae and solve other pool problems fast, look no further than Power Powder Plus 73. The highest percentage of Calcium Hypochlorite active ingredient to destroy organic contaminants, kill bacteria and control algae. At , We Know Pools, and we are your best source for the strongest Calcium Hypochlorite pool shock.

Usage Directions for Swimming Pools:

  • Add the recommended dosage of Power Powder Plus 73 during the evening hours while the filter pump is running.
  • When adding to your pool, broadcast evenly over a wide area in the deepest part of the pool. Use a clean, dry scoop to measure this product. Do not use the scoop for any other purpose. If any granules settle to the bottom of the pool, use a brush to disperse.

Superchlorination Usage Directions for Swimming Pools:

  • Every 7 days, or as necessary to prevent pool problems, shock treat/super chlorinate the pool by adding 9-18 ounces of Power Powder Plus 73 Cal-Hypo Pool Shock per 10,000 gallons of pool water to provide 5-10 ppm available chlorine.
  • Additional shock treatments may be required to correct problems which are caused by visible algae growth, high bathing loads, heavy wind, rainstorms, unpleasant odors, and eye irritation. Check the available chlorine level with a suitable test kit.
  • To prevent possible staining or bleaching, take the following steps immediately after treatment: Thoroughly clean the pool by brushing the surface of algae growth, vacuum, and cycle through the filter.
  • Re-entry into treated pools is prohibited above 4 ppm due to risk of bodily harm


Container Size:Bucket: 25 lb
Active Ingredient:Calcium Hypochlorite
Chemical Type:Shock
Product Type:Pool Chemical
Product Dimensions:11.3″ Width x 13″ Length x 10.3″ Height
Product Weight:25 lbs.