"Shock Level" amount for my pool ?

Doug C

0
Aug 6, 2011
17
I've searched for the answer to this question but can not find it. I've been reading the "SHOCK YOUR POOL" article and it mentions shock level - quote: Add enough chlorine to bring FC up to shock level (or a little higher). BUT this article does not describe or give a link, to figure out what the shock level of chlorine (bleach in our case) would be for my pool. I know I'm aiming for between 3-5ppm on a daily basis. But what am I aiming for during a shock event? I added 31oz of bleach a few hours ago (to bring FC from .5 to 4ppm in my 4,240 gal. vinyl lined pool w/ SWG), as suggested by the "Pool Calculator". But my understanding is that that is a recommendation to get me to the 3-5ppm... is that also the Shock Level? Or is the shock level a LOT more chlorine than normal (as I've been thinking)? Thank in advance. ~ Doug
 
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BTW, I'm trying to do the "shock" because my pool has become the color of lite green tea. I backwashed a couple of times today but the filter pressure is still a little high, will repeat that a few time tomorrow and see if I can lower it.
 
Richard has you covered - THE most important thing to understand is this relationship between CYA and Chlorine. When that balance gets out of whack algae can grow faster than the chlorine can kill it. It starts slowly at first and then.... green tea.

If you can post a full set of test results we'll be happy to be more specific
 
Thanks Richard320, that's exactly the chart I needed. I'll check my CYA level tomorrow.. as I recall there's a very hard to see 'black spot' (at the bottom of a skinny vial), that's supposed to disappear when checking the CYA level with the kit I have. Not easy to read even on a bright sunny day. Thanks and I'll report back if I get stumped somewhere else on this. ~ Doug
 
OK here are my numbers:

Salt = test still in progress
FC = 5
CYA = 33 or so (last drop at the top of the vial) (on my way to pick up stabilizer at the store)
pH = 7.1 (should I add 16 more oz of Borax?)
TA = 70ppm (I just added 8oz baking soda to get me to 80ppm)
CH = 150 (fine for a vinyl pool, right?)

Suggestions?
 
Yea I was hoping to shock and that's why I was trying to find the "shock level" for my pool (which would have been over 2 gals. of liquid bleach for my little pool). But before finding that out I had added 31oz's of bleach based on recommendations from poolcalculator and a big round tablet of chlorine in the skimmer basket. Today my FC is 7 . I've added 21oz of CYA also, per poolcalculator's recommendation. 16 oz of Borax to raise my PH a little. Looks like my water is slowly getting better. The remaining greenish tent I think is probably mostly my vinyl needing to be swept (will do that now). ~ Doug
 

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OH... :cry: . Well, I'll check my numbers tomorrow and see where I'm at then. Hope I didn't mess myself up too much. However, my FC being 7 for most of the day, I was starting to wonder how to get it down a bit. ~ Doug
 
Re: "Shock Level" amount for my pool ?

7ppm is not shock level for any CYA ... So why do you want it to come down? Review the chart in pool school.

Also the CYA you added may not show on the test for up to a week. So you will have to estimate based on what you added.

Posted with Tapatalk ... sorry if I sound short ... hate typing on phone ;)
 
Re:

jblizzle said:
7ppm is not shock level for any CYA ... So why do you want it to come down?

Yes I realize this but my water had been getting cleaner and cleaner throughout the day (even though I never did get it to shock level of 24ppm or whatever it was supposed to be). I think it was completely clean before I went to bed last night but it was dark (night time) and I couldn't be absolutely sure. I turned off the pump before bed for the first time in about 2.5 days or so. Therefore I was starting to wander how to get it down to normal swimming/daily use levels again. Woke up this morning and the pool it nice and clear again. No more lite green tea. So I'm thinking further "shock" is not necessary.

Today at noon:
FC = 7 or 8 approximately (my tester only goes to 5 so I'm guessing) (I did not loose any overnight)
pH = Still at 7.2ppm (It hasn't come up even though I added 16 more oz's of borax yesterday evening)
CYA = ? (I'm out of the #@*! CYA Reactant) (mini rant: why is the reactant bottles so little for the CYA, when you have to use 7ml each time you use it!)
 
How can you say you did not loose any FC over night if you were above your tests maximum level?

pH at 7.2 is fine, why do you want to raise it?

What CYA test did you buy? The TF-100 comes with MUCH more reagent than the K2006 ... one of the reason we say it is a better value while being a little more expensive.

It is possible that you managed to kill everything, but the only true way to tell is though an OCLT using the FAS-DPD test. And having CC <=0.5 and your water should be clear.

If you find that you are having to add more than 4ppm FC per day, that is another sign of something hiding in your pool
 
jblizzle said:
How can you say you did not loose any FC over night if you were above your tests maximum level?
The color of the yellow water in the test vial is above 5 and apprx 7-8 ppm today, same color as it was last time I checked it yesterday after noon. I mentioned it's just a guess.

jblizzle said:
pH at 7.2 is fine, why do you want to raise it?
Because the article titled "Water Balance for SWGs" suggests I keep it at 7.5-7.6 and add 'this is important!'

jblizzle said:
What CYA test did you buy? The TF-100 comes with MUCH more reagent than the K2006 ... one of the reason we say it is a better value while being a little more expensive.
I do plan on getting the TF-100 but being out of a job last summer and needing a kit immediately swayed me to pickup (locally) a fairly thorough HTH 6-way test kit.

jblizzle said:
It is possible that you managed to kill everything, but the only true way to tell is though an OCLT using the FAS-DPD test. And having CC <=0.5 and your water should be clear.
This pool maintenance stuff has more acronyms than I can keep up with..(sorry) what is OCLT? Also, my kit (as thorough as I say it is) doesn't mention anything about CC. The water IS clear now though. It actually calls the Chlorine test "Total Chlorine", which I've been intern calling FC (I'm realizing that could have been wrong). Anyone know for sure?
 
Correct you test is TC (total) ... you need a different test to give you FC and CC (combined chlorine ... the bad stuff). So, it is impossible to know if what you are seeing is FC or CC.

OCLT = Overnight FC Loss Test which is one of the tests to stop the Shocking Your Pool process.

Regarding the pH, I think you are fine at 7.2 for now. Actually the SWG will tend to make the pH rise fairly quickly if you do not have your TA pretty low to slow down the rise.
 
OK well at least I now know I need a more thorough chlorine tester. As a matter of fact, I think I'll just pick up one of these by itself. Unless there's something else my kit is not doing well? I can also get a refill of the CYA reagents (at a larger quantity) and anything else too.. and just stick with my meager kit.
 
tftestkits.net sells all the refills and separate tests. You want to be sure to get the FAS-DPD chlorine test ... highly doubtful you will find it locally ... it is like a "secret" test that the pool stores don't want you to know about ;)
 
I don't believe you have mentioned your CC reading. You have determined that your pool needs shocking because of the appearance which is a logical conclusion, but you also need to learn to do the combined chlorine test. Knowing your CC is one of the criteria for knowing when to shock and when to stop shocking. Without knowing this you are going to be shooting in the dark somewhat.
 

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