My first post - re acceptable chlorine levels

[gnhand]

I read much of the TFP advice this season.

My pool is a semi inground 18x33 with about 18000 gallons. I use Leslie’s 3” tabs in a auto chlorinator. I do like the concepts of TFP.

Here are my pool readings this morning:
1. CH. FC. 7.0
Cc. .2
2. PH. 7.3
3. Alk. 98
4. Ch. 130. (Low)
5. CYA. ~48
6. Copper. .1
7. Iron. .15. +/-


My question is I use the tfp advice for the high FC. based on CYA. Of around 50. The chart indicates min 4 and target of 6-8



My pool store and other research indicates that free chlorine over 4 is high for swimming. The research indicates High levels can bleach clothing hair and be unsafe for bathers and young children.

My pool water is clear. This season I’ve battled a metals problem and I’ve had evidence of greenish yellowish coffee brownish color algae on the floor of the pool.

The high recommended level of chlorine vs CYA is the question that concerns me the most.

FYI. I have owned and maintained this pool myself since the early nineties. This year has been the most problematic year ever for me.

Any and all comments will be much appreciated!!

 

[dfwnoob]

Hi @gnhand! Welcome to TFP! Glad you've decided to join us. Let's discuss a few things quickly:

My pool store and other research indicates that free chlorine over 4 is high for swimming. The research indicates High levels can bleach clothing hair and be unsafe for bathers and young children.

That is incorrect. Your proper FC level is a function of the FC/CYA ratio, which you have already alluded to. The proper FC number is ALWAYS tied to the amount of CYA in the water. Nothing else.

Here are my pool readings this morning:
1. CH. FC. 7.0
Cc. .2
2. PH. 7.3
3. Alk. 98
4. Ch. 130. (Low)
5. CYA. ~48
6. Copper. .1
7. Iron. .15. +/-

This is a Leslie's or some other pool store test, correct? We cannot offer prescriptions based on their testing since at best, it's a little inaccurate, and at worst, it's entirely wrong. You will need to invest in your own test kit - either a Taylor K2006-C or a TFTestKits.net TF-100/TF-Pro. Pool store CYA testing is notoriously poor, and unforuntately, this is one of the numbers we need to be the MOST accurate.

I use Leslie’s 3” tabs in a auto chlorinator. I do like the concepts of TFP.

If you've been reading here a while, you probably realize that, at this point, you're going to need to switch to using liquid chlorine or a salt water chlorine generator. Are these tabs the only method of chlorination you're curently using? I'm immediately suspect of the CYA test result if this is all you've been using - it should likely be MUCH higher than ~50.

We can help you get this totally under control and clean up whatever chemistry issues you might be having, but you'll need a test kit, and most importantly, to stay out of the pool store.

 

[gnhand]

Thanks for the reply.

I use a Taylor k-2006 test kit. I then post my results online to to different apps - one is Leslies and sureTREAT (located in UK

I’m thinking about try liquid chlorine since I know the tabs are stabilized and raise my CUA. I’ll think about SWG next season. I just really came upon this site a month or so ago.

I have not used liquid chlorine- this season I use exclusively the tabs in the auto chlorinator and Leslies non-chlorine powder(shock). When CC got out of balance with FC

The CYA was much higher when I had the metals problem. So I emptied about 35 to 40% of water and purchased about 12000 gallons (two truckloads ) of water. My water is well water - high iron content.

After the refill of water the CYA came down in the 45 to 55% percent area based on Taylor kit k-2006

I’m about to go to leave my house to see the Mets this evening with my sons and grandson. So I may not be able to reply till tomorrow afternoon

Thanks again. I look forward to your comments

 

[gnhand]

Thanks for the reply.

I use a Taylor k-2006 test kit. I then post my results online to to different apps - one is Leslies and sureTREAT (located in UK

I’m thinking about try liquid chlorine since I know the tabs are stabilized and raise my CUA. I’ll think about SWG next season. I just really came upon this site a month or so ago.

I have not used liquid chlorine- this season I use exclusively the tabs in the auto chlorinator and Leslies non-chlorine powder(shock). When CC got out of balance with FC

The CYA was much higher when I had the metals problem. So I emptied about 35 to 40% of water and purchased about 12000 gallons (two truckloads ) of water. My water is well water - high iron content.

After the refill of water the CYA came down in the 45 to 55% percent area based on Taylor kit k-2006

I’m about to go to leave my house to see the Mets this evening with my sons and grandson. So I may not be able to reply till tomorrow afternoon

Thanks again. I look forward to your comments

What about the problems I mentioned with high chlorine- that is over 4 for swimmers and children?

 

[mknauss]

What about the problems I mentioned with high chlorine- that is over 4 for swimmers and children?

See FC/CYA Levels
For your reported CYA of 50 ppm, you can safely swim up to 20 ppm FC. The active chlorine level at those parameters is less than that in tap water.

 

[Bperry]

What about the problems I mentioned with high chlorine- that is over 4 for swimmers and children?

See the reply above. The safe amount of chlorine cannot be untied from the CYA level.

 

[HermanTX]

My question is I use the tfp advice for the high FC. based on CYA. Of around 50. The chart indicates min 4 and target of 6-8



My pool store and other research indicates that free chlorine over 4 is high for swimming. The research indicates High levels can bleach clothing hair and be unsafe for bathers and young children.

It may be best to read this article. it is the TFP Wiki Pages. There are other articles on CYA as well.

CYA Chlorine Relationship - Further Reading

www.troublefreepool.com

 

[gnhand]

See FC/CYA Levels
For your reported CYA of 50 ppm, you can safely swim up to 20 ppm FC. The active chlorine level at those parameters is less than that in tap water.

I did not understand that - thanks

It may be best to read this article. it is the TFP Wiki Pages. There are other articles on CYA as well.

CYA Chlorine Relationship - Further Reading

www.troublefreepool.com

thanks - I just skimmed it and will read more thoughily tomorrow

 

[gnhand]

thanks - I just skimmed it and will read more thoughily tomorrow

 

[HermanTX]

thanks - I just skimmed it and will read more thoughily tomorrow

Also. I should add, are links at the bottom of the artical to other 3rd party references made in the article - so reading all of those helps bring all the points together regarding the effects of CYA on active chlorine in the pool.