pool is open - chlorine questions

EmilyOTR

Bronze Supporter
Feb 15, 2017
559
Ferndale, MI
Pool Size
15000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
so the pool store opens my pool every year. they add 4-5 gallons of chlorine and then I test and add anything else.

So, I didn't notice til after they left but they added 9 gallons of chlorine to the pool! I had some organic staining on the walls and I think perhaps that is why, but geez, my FC is like 27. That's fine but it's oddly hot right now for Michigan May and we NEVER have weather like this when we open. so my kids are dying to get in. I know we can swim at that, but I can't test pH, but from what I recall, it doesn't change much over the winter? What should I do? It's only this warm for another day or 2. Also I have a new Maytronics robot that I really want to get started (we have a ton of trees) but it says don't use in chlorine levels over 4. What? My FC is always over 4 (I have a SWG). I assume it's fine in 6 or whatever I keep it at, but what about 25?
 
Last edited:

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
37,884
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
You have to know your CYA to know if the water is safe to swim in at high FC.

See what CYA reading you get in indoor light.

If CYA 0 the FC may drop real quickly under the sun.
 

EmilyOTR

Bronze Supporter
Feb 15, 2017
559
Ferndale, MI
Pool Size
15000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
You have to know your CYA to know if the water is safe to swim in at high FC.

See what CYA reading you get in indoor light.

If CYA 0 the FC may drop real quickly under the sun.
Oh, interesting, I didn't know that CYA mattered for swimming in high FC. why is that? I'm guessing it's around 20, that's normally what I have at opening. I will test it it tomorrow. what does my CYA need to be to swim in FC of around 25?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
37,884
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Oh, interesting, I didn't know that CYA mattered for swimming in high FC. why is that?


It is safe to swim up to SLAM FC for your CYA level.

I'm guessing it's around 20, that's normally what I have at opening. I will test it it tomorrow.

Guessing doesn’t help.

what does my CYA need to be to swim in FC of around 25?

CYA 60 limit is FC of 24.

CYA 70 limit is FC 28.
 

EmilyOTR

Bronze Supporter
Feb 15, 2017
559
Ferndale, MI
Pool Size
15000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40

It is safe to swim up to SLAM FC for your CYA level.



Guessing doesn’t help.



CYA 60 limit is FC of 24.

CYA 70 limit is FC 28.
ok I won't have 60 or 70 by tomorrow, getting to that point generally take me a couple days or more. So you are saying if my FC is 24 tomorrow, to swim I need a CYA of 60? Crud. Ok, try the test indoors, I didn't know that was possible. I hate this test so much.
 

Enjoying this content?

Support TFP with a donation.

Give Support

EmilyOTR

Bronze Supporter
Feb 15, 2017
559
Ferndale, MI
Pool Size
15000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
OK, CYA is less than 20. Potentially 0. Can I now fill a sock with some? am I aiming for 60? that's what I need for my SWG anyway but if I can't get there by tomorrow, there's no swimming until the chlorine lowers?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
37,884
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Since you have a SWG add stabilizer using the sock method and squeeze the sock often. If you put the sock in front of a strong return it should dissolve pretty quickly.
 

EmilyOTR

Bronze Supporter
Feb 15, 2017
559
Ferndale, MI
Pool Size
15000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
I would sneak up on your target. Add 30 now. Test again tomorrow. You don't want to overshoot on this.

FC will still come down pretty fast.
according to pool math, I have to add more than I have (5lbs) to get to 70. I can't add 5 lbs to a sock so I won't be overshooting.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
37,884
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
I just thought of that! So, why is it unsafe to swim in a pool at FC 24 and CYA of 20?

CYA buffers much of the chlorine.

To be extreme would you fill your bathtub with bleach and take a bath in it? It is not good for your skin or other body parts.
 

EmilyOTR

Bronze Supporter
Feb 15, 2017
559
Ferndale, MI
Pool Size
15000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
CYA buffers much of the chlorine.

To be extreme would you fill your bathtub with bleach and take a bath in it? It is not good for your skin or other body parts.
that makes sense, thanks. Ok I have 3 socks going tonight, unfortunately I'm going to be able to go out and squeeze once more before I go to bed.
 

EmilyOTR

Bronze Supporter
Feb 15, 2017
559
Ferndale, MI
Pool Size
15000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
I just thought of something - doesn't it take a few days after adding CYA to see it in a test? Am I just relying now on FC level coming down to let the kids swim today? and I'm preventing that by adding all this CYA? lol oh man.
 

Enjoying this content?

Support TFP with a donation.

Give Support
Thread Status
Hello , This is an inactive thread. Any new postings here are unlikely to be seen or responded to by other members. You will get much more visibility by Starting A New Thread