Cal Hypo - Bleach equivalents`

Tyrone Shuz

LifeTime Supporter
Jun 2, 2007
54
#1
"Ben" said 1 gal bleach = 3/4 lb of shock.

But I think that was the old 5.25% solution.

I use HTH 60% available chlorine (less stabilizers)

What is the ratio of Gallons of bleach to 1 lb bags of cal hypo?
 

gonefishin

LifeTime Supporter
Apr 5, 2007
413
Joliet, Il.
#2
Hi Tyrone,

What's the comparison for? If you want to know what your "shock" levels are...you can use the best guess CYA chart and the bleachcalc program. (both of which are linked in my signature)

dan
 

Tyrone Shuz

LifeTime Supporter
Jun 2, 2007
54
#3
Bleach Calc will only tell me how much bleach to add to raise my Cl.

I'd like to know how much Cal Hypo to add. I have a bunch of it, it's easier to store than bleach (I don't have the room for a whole summer's worth of bleach). I don't like running to the store all the time for bleach, so Cal Hypo is much more convenient. The stuff I used to use was HTH 68%, but I think a lot of folks bleached their liners with it, so they cut it down to 60% and it also dissolves easier.

I need a converter from 1 lb bags to gallons of bleach. Even better would be a converter that would not only do 60%, but any % available chlorine.

I'm still going to use a mixture of bleach and cal hypo, moving to more bleach if it becomes convenient to hit the stores or if I can clear out a closet. Can't store it in the shed, it gets too hot.
 

Tyrone Shuz

LifeTime Supporter
Jun 2, 2007
54
#4
Hah. In the new neato-torpedo test kit which you can get thru this very website, on the inside of the blue box w/the quick CL test and the pH test, there's a chart that shows the various CL percentages and how much it raises your CL count depending on the size of your pool. Very cool. I think the numbers don't match perfectly w/my pool, but it's close enough.
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,082
San Rafael, CA USA
#5
1 gallon of 6% bleach is equivalent to 12.8 ounces weight of 65% Cal-Hypo or 17.3 ounces of 48% Cal-Hypo or 13.9 ounces of 60% Cal-Hypo (I haven't heard of that particular concentration).

1 pound of 60% Cal-Hypo will raise the FC by 7.1 ppm in 10,000 gallons (65% Cal-Hypo will raise the FC by 7.7 ppm while 48% Cal-Hypo will raise the FC by 5.7 ppm).

Ben's rule of 1 gallon of 5.25% bleach being equivalent to 3/4-pound of Cal-Hypo would be for 60% Cal-Hypo.
 

Tyrone Shuz

LifeTime Supporter
Jun 2, 2007
54
#6
Thank you /very/ much for that breakdown!

As far as 60% concentration, that's what HTH Shock & Swim is. The product I used to use (and can't seem to get any more, at least locally) was HTH Super Sock-it which was 68%. The Shock & Swim does dissolve a lot easier, but I obviously need more of it.

Also, I don't measure till about 4 hrs after I shock, because that's how long it takes to turn the pool over through the pump. If my CYA is low (which it has been) I'll lose a bunch of it in that time, so it's hard for me to get an accurate read on how much it raises the FC.
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,082
San Rafael, CA USA
#7
You shouldn't need to wait 4 hours, or one turnover, to take a chlorine reading. If you have decent circulation and add the chlorine over a return in the deep end or slowly into the skimmer then the chlorine will diffuse readily throughout the pool within 30 minutes (even 20 minutes will be reasonably accurate if you have a pool drain as well as skimmer). I did an experiment using a pool dye as well as by measuring chlorine and found that this is how long it took. Think of it this way: if you had only a stirrer and didn't run any of the water through the pool filter, it would still get dispersed. It's the water flow within the pool that does most of the mixing and has very little to do with actually forcing one volume full of water through the pump and filter.