"Normal" FC loss during daylight hours

[Jkpharm]

I know there is probably not a "normal" amount of FC loss over the course of daylight hours due to different issues. However, is a loss from 12.5 at noon to 6.4 at 10pm too much? We did have significant and multiple thunderstorms yesterday afternoon. I'm told that has an effect on chlorine? I'm too new at this ...

 

[jcowart]

The first question is what is the CYA level. With no or little CYA then it could be normal. Most well balanced pool average 2 to 3 ppm a day. Storms have little effect on pool chemistry.

 

[Texas Splash]

I would say that while that much of a loss can be "explained", it's not what we call normal or ideal. As noted above, that's too much to be losing each day, but without knowing your current CYA (stabilizer) level, we can't really answer that question. Do you have either the TF-100 or Taylor K2006 test kit to test CYA for yourself? If so, let us know what it is, otherwise, you really need one of those kits to check yourself. Cheers!

 

[Jkpharm]

This morning's numbers:
FC: 5.2
CC: 1 (I know not good -- addressed on another thread)
pH: 7.5
CH: 500 (I know too high)
TA: 110
CYA: 60

 

[Patrick_B]

Aside from the Stabilizer (Cya) level being low the only other things getting your Chlorine are organics in the water. Rain has very little effect on pool chemistry. Very little unless we are talking about many, many, repeated inches of rainfall.

 

[domct203]

Aside from the Stabilizer (Cya) level being low the only other things getting your Chlorine are organics in the water. Rain has very little effect on pool chemistry. Very little unless we are talking about many, many, repeated inches of rainfall.

I'm confused. I thought a CYA of 60 would be considered high for a non-SWG pool?

http://www.troublefreepool.com/content/128-chlorine-cya-chart-slam-shock

This morning's numbers:
FC: 5.2
CC: 1 (I know not good -- addressed on another thread)
pH: 7.5
CH: 500 (I know too high)
TA: 110
CYA: 60

If your CYA is indeed 60, you should be targeting a FC of 7-8ppm, 5ppm would be the minimum.

As stated, a CC of 1ppm shows that something nasty is brewing.

I would SLAM at 24ppm. Ideally you should drain 30-50% of the pool and refill to lower that CYA first, if you can get to CYA 30 you can cut the shock level in half (12ppm vs 24ppm).

Dom

 

[Scuba_Steve]

https://www.troublefreepool.com/~richardfalk/pool/ChlorineLoss.gif

 

[swoopman]

CYA of 60 is considered high for a non-SWG pool.

I believe Partick's response was to your original post and he was saying that a low level of CYA can cause a high amount of chlorine loss in a day.

 

[jblizzle]

https://www.troublefreepool.com/~richardfalk/pool/ChlorineLoss.gif

This is not a simple plot and I think it might be confusing to a new member ... they will not know the difference between a FC ppm and how to get the ppm Cl2 which is what the lines represent.
In fact, the more I look at it, the more I am getting myself confused by it.

 

[Patrick_B]

60 is high for a Non Salt pool. I was merely making a statement of fact about day time loss.

 

[domct203]

60 is high for a Non Salt pool. I was merely making a statement of fact about day time loss.

OK, I understand. I guess it was the fact that the post was made right after the OP posted his numbers that made me think you were referring directly to the CYA=60 info.

Sorry for any confusion I might have created.

Dom