Scientific evidence that hi FC is safe

[AJB1234]

Hi!

My wife is a microbiologist and is concerned about 2-3ppm of FC in the pool I've noticed that I need FC closer to 5-6 to prevent algae. TFP says FC up to (pool specific) slam levels are safe for swimming if the water is still clear. Do you have any science to back this that I might share with the wife?

Thanks, AJ

 

[ajw22]

Didn’t we go through this last year with the discussion about CYA levels? FC and CYA levels are interrelated in that higher CYA levels allow most of the higher FC to be buffered. The amount of active chlorine is small.

Pool Water Chemistry

This thread presents my findings so far on pool water chemistry including the following: More Accurate Calcite Saturation Index (CSI) to replace Langelier Saturation Index (LSI) Calculation of ppm HOCl (disinfecting chlorine) at various levels of Total Free Chlorine (FC) and Cyanuric Acid (CYA)...

www.troublefreepool.com

 

[AJB1234]

Yes! And TFP successfully got her to accept a higher cya level as a result. Now I'm realizing how much chlorine my pool requires to be algae free and its much more than expected. thanks for helping out!

 

[mknauss]

Hate to bring it up, but apparently the UV and Ozone devices did not work as advertised?

 

[Oly]

Safe drinking water FC levels can be 4ppm and witout CYA.

 

[AJB1234]

Yes... I am not that happy with the ozone and uv but maybe I would need even more fc without it... not sure. We know ozone technology works but it seems not powerful enough to reduce the fc to levels we were hoping for

Good to know about 4ppm for drinking water.

 

[AJB1234]

Just curious... why do so many people and manufacturers recommend 1-3 ppm of chlorine?

 

[ajw22]

Just curious... why do so many people and manufacturers recommend 1-3 ppm of chlorine?

Those are government standards from the 1970s that have never been updated with more modern science. No one has a reason to invest in the update. Manufacturers just copy the same guidelines they have used for decades into manuals.

 

[AJB1234]

That's interesting thanks for sharing.

 

[Flying Tivo]

Your UV device is consuming FC, just so you know!

 

[Msch99]

Some manufacturers have a $ incentive NOT to update! ?

 

[AJB1234]

Safe for the manufacturers to stick with the government standards.

Didn't know about the uv consuming chlorine... how much does it consume?

 

[Msch99]

Isn't it the UV rays from the Sun that consume CL in our pools?

 

[Wobblerlorri]

I'm a microbiologist too, and the evidence presented in several threads here convinced me that high levels of FC are adequately buffered by CYA so as to be not a problem with swimmers.

 

[Wobblerlorri]

Isn't it the UV rays from the Sun that consume CL in our pools?

UV rays, oils, skin flakes, algae, fungus, and all the cooties on the human body eat up FC. Ran an accidental experiment last night -- I had raised my FC to 24 for mustard algae, and my son got in it before I could warn him. He didn't explode, and I lost 4 ppm from him getting in the pool. We had tested at 8 pm, he got in at 9, and I tested again at 10 pm. Nighttime, no UV. One human body ate up 4 ppm FC!

 

[AJB1234]

Good to know... if not too difficult, can you share those threads? How much maximum fc are you comfortable with?

 

[Wobblerlorri]

Post #7 on this thread convinced me.

Is 10ppm FC safe to swim in?

I remember hearing that generally Free Chlorine levels can be much higher than the pool stores will recommend. I was having a problem getting my FC to hold. Last night, I finally decided to do a good shocking. I used 3 gallons of 10% bleach. By morning my FC was holding at 11ppm. Later that day...

www.troublefreepool.com

That said, I wouldn't make a practice of swimming at 24 ppm FC like my son did, but the normal ranges on the FC/CYA Levels are certainly safe.

 

[AJB1234]

Thanks will share with the wife.

 

[markayash]

Test the level in your drinking water and you might be shocked. and we dont just bath in it we drink it!!

 

[AJB1234]

I'm doing that!