bleach vs shock for achieving very high FC

TaraT

Member
May 15, 2017
16
Downsville, LA
hey there just wondering what the benefit is to using standard liquid bleach for very high mustard algae shock level vs using bags of shock?? 20 jugs of bleach or a few bags of shock..... Why do we choose bleach?

Thank You!!!
 

Jezza

LifeTime Supporter
TFP Guide
Jan 18, 2015
969
Bunbury, WA, Australia
Mainly because it doesn't add anything else (apart from a bit of salt).

All solid forms of chlorine either add calcium or CYA which when added can create further problems especially when they get too high.
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,397
San Dimas, CA (LA County)
In a pool your size, 20 121oz jugs of 8.25% bleach will raise FC by 59 and add 98 ppm salt

It takes 232 oz trichlor to add 59 FC. It also adds 36 CYA, 48 salt, and lowers pH and TA
It takes 384 oz dichlor to add 59 FC. That will add 54 CYA, 48 salt, and also lower pH and TA
It takes 294 oz Cal-hypo 73% to add 59 FC. That will add 42 CH and 60 salt.

You can't do anything about the salt. But do you need extra CYA or CH? Raising the CYA will also raise the mustard shock level. So you'd need more powdered shock, which will raise the CYA level, which will raise shock level, and so on and so on in a hopeless spiral. Do you want to have to deal with pH and TA after you're done? CH isn't necessary for a vinyl lined pool, and adding a whole bunch at once may also cloud the water for a day or two, which makes it hard to see any progress. If you'd rather use the powder, then Cal-hypo would be the best choice, but make sure you have room for the CH. Vinyl pools won;t etch like a plaster pool but they can still get scale.
 

atttech-2

Bronze Supporter
TFP Guide
Jul 24, 2015
1,176
Central Valley CA
As Jezza said with liquid you mostly only get FC. Most people with green pools end up here because they use powdered forms and end up with crazy high CYA leading to needing to maintain ever higher levels of FC for the same amount of sanitation. Cost can also be a benefit, liquid usually is less expensive per unit of FC delivered. So unless you know you have low CYA and/or have some shock on hand liquid is the way to go.
 

TaraT

Member
May 15, 2017
16
Downsville, LA
ok wow. thanks for the info. CYA was high due to me mistakenly adding too much. CYA 115 so am partially draining now. I do have dichlor (from before finding and agreeing with TFPC!) Should i just use it since i have it? as long as I can start with not too high of CYA...... I was hoping to get it down to about 70-80 but i could even drain a little more and get it lower to compensate for using dichlor. and if i understand you correctly....Cal-hypo won't add CYA at all right? and my CH is fine @ 100
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,397
San Dimas, CA (LA County)
ok wow. thanks for the info. CYA was high due to me mistakenly adding too much. CYA 115 so am partially draining now. I do have dichlor (from before finding and agreeing with TFPC!) Should i just use it since i have it? as long as I can start with not too high of CYA...... I was hoping to get it down to about 70-80 but i could even drain a little more and get it lower to compensate for using dichlor. and if i understand you correctly....Cal-hypo won't add CYA at all right? and my CH is fine @ 100
Don't use the dichlor. Just because you have it is a lousy reason. As long as the bag is sealed, it'll keep for years and years. Save it for next season when you need to raise CYA.
 

TaraT

Member
May 15, 2017
16
Downsville, LA
ok it was big bucket bought from sams. already opened. but youre right i can save. so would you still recommended bleach vs cal-hypo considering i have room with my CH and Salt???? again i really appreciate your time!!
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,397
San Dimas, CA (LA County)
ok it was big bucket bought from sams. already opened. but youre right i can save. so would you still recommended bleach vs cal-hypo considering i have room with my CH and Salt???? again i really appreciate your time!!
I recommend bleach simply because other people will be reading this thread and if they have a pile of cal-hypo leftovers they'll want to use it because you did, but they may not have room for the additional CH if they've been using it all along.

It's your pool, so you can add whatever you want. I'd do the math and see if Cal-hypo or bleach works out cheaper. How much is 19 pounds of cal-hypo compared to 20 jugs of bleach?
 

pabeader

LifeTime Supporter
TFP Guide
May 14, 2015
4,349
Cartersville Ga
Silly question..... are you talking about regular old house hold bleach or liquid chlorine?
Yes regular household bleach and liquid chlorine are the same thing as far as active chemical is concerned. The difference between the two is usually the %.
Bleach is usually 6% or 8.25% liquid chlorine usually is 10% or 12%
 

Zindar

Well-known member
Jun 4, 2011
207
Austin, Texas
Don't use the dichlor. Just because you have it is a lousy reason. As long as the bag is sealed, it'll keep for years and years. Save it for next season when you need to raise CYA.
Exactly what I did. I had chlorine pucks and dichlor left over from before I found this site; fortunately my CYA never got high because I found this site soon enough before that happened. After enough seasons, I eventually used all my chlorine pucks and dichlor to maintain the correct CYA, and just at the end of last season finally ran out, and I have no intention buying any more of that.
 
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