Why my pool doesn't hold chlorine?

Justify

Well-known member
May 7, 2019
49
Iowa
Happy 4th!
I slept in and didn't tested and adjusted till 9am. It was 12 ppm, added 88 oz of 12.5% bleach. I plan to test/adjust again around 4pm and then at 10 pm.
It is safe for kids to jump in meanwhile? Hot hot day here.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,279
Laughlin, NV
You can safely swim in a pool as long as the FC is above the minimum and at or below SLAM level based on your CYA. You must also be able to see the bottom of the pool in the deep end of the pool.
 
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Justify

Well-known member
May 7, 2019
49
Iowa
Thanks.
Also, normally I dump the water from the chlorine test tube as soon as I am done with testing. This morning I was in a hurry, so I didn't dump it until after I was done with adding bleach into pool, and I found out the (previously clear) water turned back to deep pink meanwhile. Is it normal or does it mean the FC might be actually higher?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,279
Laughlin, NV
The FC test if left after you get to clear will turn pink again. Ignore that. The test is complete when it turns clear the first time.
 
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Justify

Well-known member
May 7, 2019
49
Iowa
So it looks like I am done.
Yesterday, I tested and adjusted FC three times (added 2.5 gallon of 12.5% bleach total yesterday)
9:30am 12ppm - added 88 oz
6pm 10.5ppm - added 121 oz
11:45pm 12.5 - added 99 oz

This morning @6:45am, FC was 16.5

Two questions:
When can I turn the SWGC back on?
When it is safe to raise CYA? (I don't want to hurry with it in case I find out I got mistaken somehow and need to continue SLAMming)
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,279
Laughlin, NV
So all three criteria passed?
Once that occurs, start adding CYA in increments to get to 70 ppm. Let the FC drift down to target range and start the SWCG. I would set the SWCG to initially generate 4 ppm FC per day and then monitor FC to adjust up or down as necessary.
 

Justify

Well-known member
May 7, 2019
49
Iowa
Yes I believe all three passed, I forgot to mention, I also tested CC this morning and it was 0 (no pink after reagent addition).

So my FC target is 4ppm right? How long would it take for the chlorine to go down? (just to know when it makes sense to test again, as I don't want to waste my reagents)

My CYA target is 70 right? Does it make any difference that the pool is (auto)covered most of time (I know indoor pools require lower CYA but couldn't find anything about CYA vs. autocover)
I admit I am kind of worried to raise CYA... what if I need to SLAM again...
 
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mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,279
Laughlin, NV

It can make a difference with an autocover. You do not show that in your signature. Please add it.

You can go with a lower CYA - I would target 30-40 ppm. Target a FC of 5ppm so you have a reserve when you open the cover and swim.

For how much the SWCG should generate, you will have to play with that. Really depends on how often you have the cover open. I do not see that you have any form of automation so you will be having to adjust the SWCG settings often at the pad.
 
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Justify

Well-known member
May 7, 2019
49
Iowa
I updated my signature. All the time, it thought it was there. Sorry. I will probably update more later. I am really in 'the dummies' category when it comes to the pool equipment so I need to consult with my husband. What I put in my signature was what our contract said when we built one year ago.
That's great news that my CYA can be lower. Since many people have autocover now, maybe it would be good idea to update the Chlorine/CYA chart - add the autocover option? Not sure who should I address this suggestion to.

Also, please, when can I expect the numbers to go back to normal, especially FC and pH? I don't mind testing frequently but I don't want to waste my reagents, especially my 0870 powder and 0871 liquid.
 

mguzzy

Gold Supporter
Jul 8, 2015
2,384
OV, CA
It will drift down based on your normal daily Cl loss. Expect it to take a few days. If you test your pool 24 hours apart you can get an idea for the CL loss day to day.. and then not check it for that time frame. (unless you want to). For me when I am coming down from high FC I turn my SWG on to its lowest setting so it can chew on any CC's in the water.

Edit and additions: Just 'cause composing and auto correct on my phone is maddening..
 
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