Forced to use “Shock” product

Household6

LifeTime Supporter
Sep 15, 2013
623
Fayetteville, NC
Shortage of LC and bleach in our area is forcing me to use granular shock for the first time. Went with Cal Hypo as our pool eats calcium anyway.

I waited too long and water is going green, so need to SLAM. CYA is 50.

Directions on package (HTH Super Shock, 56.44% Cal Hypo) say to use just shy of 3 lbs for our 38k gallons. TFP app (for 53% cal hypo) says to use 12 lbs (12 bags!) for SLAM. (Pretty big difference!)

How much do I use? And how often should I expect to check the FC since this is granular? Anything else I need to know?
Thanks guys!
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
44,029
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
That amount of Cal Hypo, 12 lbs, is to add 20 ppm FC to your pool. That is SLAM level. You should dissolve the product in small batches in a bucket and pour into the pool at return with the pump running.

Then test your FC every couple hours and add more chlorine to get to 20 ppm FC.

Try to find liquid chlorine.
 

Wobblerlorri

Bronze Supporter
Apr 16, 2019
1,794
Bremen, GA, 65 m west of Atlanta
Pool Size
4024
Surface
Vinyl
Chlorine
Liquid Chlorine
Sources of pool chlorine are Wal-Mart, Home Depot, Lowe's, Ace Hardware, and your local pool store. Don't forget you can also use plain old bleach, no additives or Cloromax, which runs 6%. There's usually plenty of POB around, if you can't find the good stuff anywhere.

I've posted before how to check the strength of POB using pool math. Here's the link
 

Household6

LifeTime Supporter
Sep 15, 2013
623
Fayetteville, NC
That amount of Cal Hypo, 12 lbs, is to add 20 ppm FC to your pool. That is SLAM level. You should dissolve the product in small batches in a bucket and pour into the pool at return with the pump running.

Then test your FC every couple hours and add more chlorine to get to 20 ppm FC.

Try to find liquid chlorine.
Exactly what I needed to know. Thanks!
 
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