Pool Shock Power Blast (68% Cal Hypo) 6x1 Lb Bag - R20841-6



Model # R20841-6

  4.65 Average  



Model # R20841-6

Product Description

Cal-Shock 65  

Power Blast Cal Shock 65 is 68%CalciumHypochlorite with 65% available chlorine. Our best selling shock treatment, Cal Shock 65 is in a fast dissolving granular form so it quickly destroys organic waste, algae and bacteria saving you time and money. 
  • 1 lb bags Calcium Hypochlorite
  • Powerful shock treatment great for spring start up
  • Gives quick chlorine boost
  • Ensure pool water is balanced for best results
  • Complete instructions for dosage on container
  • Compares To BioGuard Burn Out
Pool Volume in gallons Amount of Shock needed weekly if pool is clear Amount of shock needed if pool is green
10,000 gallons 1 lbs. 2 lbs.
20,000 Gallons 2 lbs. 4 lbs.
25,000 Gallons 2.5 lbs. 5 lbs.
30,000 Gallons 3 lbs. 6 lbs.
35,000 Gallons 3.5 lbs. 7 lbs.
40,000 Gallons 4 lbs. 8 lbs.

*Always follow the manufacturer's recommendations/directions located on the product container.Store any un-open bags in a cool and dry location
For More Pool Chemicals

Product Specifications

# of 1 lb Bags:

?     Asked on 5/3/2017 by scott Drezdzon

what do you recamed for pool openings

A     Answered on 5/4/2017 by InyoPools Product Specialist Stacey M.

Hello, We have Spring start up kits listed here. These kits provide algaecide, shimmer, stain/prevent, and shock.

?     Asked on 9/27/2016 by

Can this product be use as a regular chlorination instead of liquid chlorine?

A     Answered on 9/28/2016 by InyoPools Product Specialist Alan M.

Hello, Yes the Pool Shock Power Blast is available as the perfect shock substitute for liquid chlorine.

?     Asked on 6/7/2016 by


A     Answered on 6/7/2016 by InyoPools Product Specialist Alan M.

For a 1,000 gallon pool, you would need to add 1.6 oz weekly. If the pool size was listed in error and the pool is 10,000 gallons, you would need to add 1 lb weekly. We also recommend you test your pool water weekly to determine if your chlorine levels are low and require shocking prior to adding Power Blast Pool Shock.

?     Asked on 4/13/2016 by Sparky

What are the active ingredients of Calshock-65?

A     Answered on 4/13/2016 by InyoPools Product Specialist Lennox H.

Hi Sparky, The active ingredients of the Cal-Shock 65 is Calcium Hypochlorite, 65%.

?     Asked on 4/11/2015 by

Does this have algeacide? I want to avoid the ones with algeacide because I want to use it for potable water.

A     Answered on 4/13/2015 by InyoPools Product Specialist Hector F.

This item does not have algaecide but can kill algae.

?     Asked on 9/10/2014 by Guest

When using Blast-it 65 to shock is it best to broadcast around pool?In Skimmer? or dilute in bucket first?

A     Answered on 9/10/2014 by InyoPools Product Specialist Patrick P.

The shock can be added to a bucket of water to pre-dissolve it before adding it to the pool. Shock should NEVER be added through the skimmer.

?     Asked on 12/20/2012 by Guest

I constantly have an algae build up in one corner in my swimming pool. What can I do to get rid of it?

A     Answered on 12/20/2012 by InyoPools Product Specialist Patrick P.

I would recommend aiming the return fitting downward and towards the steps. This should help circulate the water around the steps better. I would also recommend brushing down the pool and using a chlorine shock.

?     Asked on 10/25/2012 by Guest

When is the right time to shock my swimming pool?

A     Answered on 10/25/2012 by InyoPools Product Specialist Patrick P.

A swimming pool should be shocked every 7-10 days. It is recommended to shock the pool during the evening hours so that the sun doesn't burn off the chlorine.

?     Asked on 10/25/2012 by Guest

Is it true that if I have a vinyl pool I can only use liquid shock?

A     Answered on 10/25/2012 by InyoPools Product Specialist Patrick P.

You can use granular or powdered shock with a vinyl pool as well. Before adding the shock to the pool, you want to add it to a bucket of pool water to pre-dissolve it.

?     Asked on 10/18/2012 by Guest

My pool company recommends using a phosphate remover. Do you have any such item?

A     Answered on 10/18/2012 by InyoPools Product Specialist Patrick P.

I would recommend using  Phosfree. The product container has easy to follow directions and will help you eliminate your phosphate problem.

?     Asked on 10/18/2012 by Guest

I have an in ground pool with a mesh winter cover. Several weeks ago, I had added 2 gallons of chlorine to the pool. Since then, with the mesh cover still on, the water has turned green. I've been adding about a gallon of shock each week without improvement. Should I continue adding shock to the pool or should I wait?

A     Answered on 10/18/2012 by InyoPools Product Specialist Patrick P.

I would recommend waiting until the pump and filter are running again before adding any more shock to the pool. Algae needs two things to grow: food and light. With a mesh winter cover, the algae has more than enough light to grow regardless of the shock that you're putting in. Also, shocking the pool without circulation can cause bleaching of the pool surface

?     Asked on 10/12/2012 by Guest

Can I add shock through my automatic chlorinator?

A     Answered on 10/12/2012 by InyoPools Product Specialist Patrick P.

No, you should never add shock through an automatic chlorinator. Never mix different types of chlorine. Pool shock can be added to a bucket of water and poured directly into the swimming pool.

?     Asked on 1/25/2012 by Guest

I'm looking for pool shock to sanitize my drinking water. Will this work?

A     Answered on 1/25/2012 by InyoPools Product Specialist Patrick P.

I have heard of people using pool shock to sanitize drinking water but I can not promote the use of any pool shock for this purpose. You will want to contact the NSF for further information.


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