Make me feel better please - Chlorine kills all things right?

JimMarshall

Gold Supporter
TFP Guide
Jun 5, 2017
1,003
Oil City PA
My soon to be 3 year old just got diagnosed with a viral Cocksackie viruses infection that causes the childhood disease commonly known as hand foot and mouth.... he was recently swimming in the pool, within the incubation period of the virus, when he would have been (extremely) contagious.

As as long as I’ve continued to maintain my proper FC/CYA, I have no special precautions I need to take, correct ? Chlorine kills all things and I need to take no action to protect future friends, cousins, etc that are using the pool in the coming weeks?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
19,237
Northern NJ
I am not a doc but looked at Coxsackievirus on Coxsackievirus Incubation Period, Symptoms & Treatment It looks like the methods of transmission are from surface contamination and the virus does not live in the water.

Chlorine does not kill everything. There are interesting bacteria that can survive in the water. I once had a cut in my finger that did not heal. Went to my very good doc who diagnosed some type of bacteria you usually get when swimming in a lake. I don't remember what the name was. I have never been in lakes but my hands were in my pool.
 

ctrav

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TFP Guide
Apr 23, 2017
2,400
Northlake TX
I’m no doctor but I found this if it helps...

[FONT=&quot]HFMD is contagious and tends to spread most easily in settings where many young children are together, such as day care centers. In tropical parts of the world, HFMD is present throughout the year, but in cooler climates, such as New York, outbreaks take place only in the summer or fall. Some people incorrectly believe that the illness is spread in swimming pools, but a properly chlorinated pool should kill the virus.

it also states the contagious period is during the first week. Was your child in the pool during this period? If it were me I would keep others out of the pool, take the FC up to shock level, let it dissipate and then keep my FC a little higher for awhile.

Those are just my personal thoughts and hopefully a TFP expert with much more experience than myself will chime in...best wishes for your young one![/FONT]
 

Poolzzz

Well-known member
Aug 14, 2017
373
Vancouver, BC
The CDC link is a good one. It shows the 99% kill CT factor for the Coxsackie A virus as 0.15 and Coxsackie B as 2.25.

Correction to the above post however is the chlorine levels are not "very low FC levels compared to pool concentrations" but actually higher than our shock level.

Still at our shock level the kill time would work out to be about 6 minutes. It would be around an hour at our minimum FC levels in the Fc/CYA chart.

So people in the pool at the same time would be at risk. But go to shock level for a bit and you should be good going forward assuming they are no longer contagious.

Here's a post from Chemgeek for some background on the general subject: Chlorine Kill Time
 

setsailsoon

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LifeTime Supporter
TFP Guide
Oct 25, 2015
3,325
Stuart/FL
The CDC link is a good one. It shows the 99% kill CT factor for the Coxsackie A virus as 0.15 and Coxsackie B as 2.25.

Correction to the above post however is the chlorine levels are not "very low FC levels compared to pool concentrations" but actually higher than our shock level.

/QUOTE]

Pool, just trying to understand. How is it the FC levels are lower than pool levels? They are less than 1 mg/L (same as ppm).

Chris
 

Poolzzz

Well-known member
Aug 14, 2017
373
Vancouver, BC
Chris, their numbers assume no CYA in the water. We use CYA which greatly weakens the effect of chlorine. That's why we can easily swim with FC=10 (at CYA=50) but the same FC level in an indoor pool would burn your swimsuit off! Lol

A good rule of thumb is the ratio of FC to CYA approximately equals the FC with no CYA. Example, given CYA of 50 then FC=10 is eqivalent to 0.2 FC without CYA.

This concept is a cornerstone of the TFP process and embodied in the FC/CYA chart that we all use to set the proper chlorine levels in our pools.