How much bleach is to much..

TTKing

Member
May 15, 2007
15
Long Island, NY
First post on the site, woohoo!

So how much bleach is too much when you have a vinyl liner? I think i might have over did it when adding "liquid shock" (12.5%) to the pool. I think the FC is hovering around 20 PPM... I think, Its the best guess i could come up with with the test kit that im using (Taylor 2005). If 20 ppm is alright, how high FC ppm could I get up to without having vinyl issues?

Thank you!
 

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
9,607
SW Indiana
Welcome. Safe chlorine level depends on your CYA level. Most agree that 15ppm is always safe. You probably won't hurt anything with a short excursion at 20ppm, but I wouldn't make a habit of it unless your CYA is high enough.
 

The Mermaid Queen

TFP Expert
LifeTime Supporter
Mar 28, 2007
2,522
Northern KY
Welcome to TFP! You've come to thr right place for all your pool care needs, and some other stuff too!! :thequeen:

We need to know your other test results, especially CYA or stabilizer, to help you proceed. If you have an unstabilized pool, 20FC is WAY too much. "How much FC" depends on your CYA.

The only risk to a vinyl liner, to my knowledge, is fading. I suppose if you were using a powdered product and it sat on the bottom, or if your FC was always way too high, the lifespan of the liner could be shortened.

Someone who knows more than I will be along shortly!
 

thilbert

Member
May 1, 2007
5
Hurst, Tx
With a CYA of 0 (zero) when I open, for the last three seasons, I shock to 35 to 40 ppm until I kill off all the algae. I have not noticed a degredation in my liner, nor have I noticed a bleach out condition on my liner. I should also add that the liner is 11 years old. I am not recomending you go to these levels, just that I have done so without any appreciable harm to my liner. Your mileage may vary.
 

TTKing

Member
May 15, 2007
15
Long Island, NY
Sorry! CYI is between 50 and 60. I have an SWCG and actually need to raise it a bit more.
Thank you for the warm welcomes and quick reply's! wow!

Let me awnser my own question then.. So because the CYI is the level its at I shouldnt have a problem and that should actually be my shock level then, is this correct?

Thilbert, you have just made my day.. I needed to hear that.
 

The Mermaid Queen

TFP Expert
LifeTime Supporter
Mar 28, 2007
2,522
Northern KY
With a CYA of 50-60, 20 for shocking will not be a problem. Check out the Best Guess table, posted in various places here. When I have a bit more time, I will link it.

CYA 30-50...shock 15
CYA 60-90...shock 20

So you are correct!

(Welcome thilbert!!)
 

thilbert

Member
May 1, 2007
5
Hurst, Tx
Thanks Queen!

I also wanted to add that I don't necessarily endorse what I do for anyone elses pool. I have had success at MY method for MY pool and I do it because I can get results faster, which does not equate to better. I think that "bleaching" a liner due to high levels of Cl may be a dubious claim. This is based solely on my experience. For example, before I took over the management of our pool, my then fiance had a service do it. They used either powdered Cal-Hypo or Powdered DiChlor and would just dump it in the pool (not broadcast) in one lump whether the pump was circulating the water or not.; It would often just sit there for a day before disolving completely. I've not ever noticed bleached out spots and I occasionally scuba dive my pool to remove pebbles and perform inspections of the liner.