Model # R20841-48

Alternate Part #'s LZA71428A

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 1/25/2012by 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.

?     Asked on 10/19/2012by Guest

No matter how much chlorine shock I put in my pool the chlorine level is always low. What can I do?

A  Answered on 10/19/2012 by InyoPools Product Specialist Patrick P.

I would first make sure that you are testing the total chlorine AND free chlorine. If they are not the same reading, you may have a chlorine lock. If the chlorine levels are the same, I would check the pH, alkalinity and cyanuric acid levels.

?     Asked on 10/25/2012by 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 10/25/2012by Guest

My swimming pool is clear but when my kids and I went swimming, our eyes burned. My neighbor came by and checked and said that the pool should be fine because he can smell the chlorine. What is wrong with my pool?

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

It sounds like you have chloramines. Chloramines are formed any time ammonia and nitrogen are in the water. Chloramines smell bad and cause skin and eye irritation. You can resolve the problem using this method.

?     Asked on 12/20/2012by Guest

I think I have a chlorine lock in my swimming pool. How did I get it and how can I get rid of it?

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

Chlorine lock is a condition in your swimming pool when the chlorine levels ( free chlorine and total chlorine) are not the same which makes the chlorine useless. You can read more here.


Review Summary

 (Average 4.75  out of 5 stars)
4 Rating
5 star:
4 star:
3 star:
2 star:
1 star:

The Most Helpful Review

The Most Recent Reviews