can a person detect the difference between fc6 and fc4

[engrav]

Had family swimming.
Kids said "cool" but one adult said "too much chlorine" (did not know the fc level)

next day I let it drop from about fc6 to about fc4 and asked "how was the pool today?"
she said "much better"

can some persons distinguish fc about 6 from fc about 4?

or...

 

[pooldv]

What is your CYA level?

 

[engrav]

sorry
CYA about 30
pH about 7.6
TA about 80
CH about 260
water clear

 

[woodyp]

I wouldn't think so, I never have. Sounds like you have an individual who is overly sensitive to chemicals at the most to me.

 

[jv92red]

Your questioning was misleading as they expected you to fix it from their complaints the day before. The next time they complain, make a note to RAISE it up 2ppm that next day and then ask them "So yesterday was a little high... so how is the pool today?" I bet you'll get the same answer: "Much better"

BTW, if they are smelling chlorine I would bet there are CC's in there that they are noticing.

 

[chem geek]

If they were churning the water then they can volatilize the chlorine in it and yes a higher FC level at the same CYA level will smell a bit more, but chlorine has a "clean bleach" smell and not a "bad pool smell".

 

[wjr75]

I've had people ask if I have a salt water pool because I don't smell any chlorine. When in fact I had 8ppm FC with 45 CYA and no salt water.

 

[klynne]

fc has no smell but tc will stink you out of the POOL

 

[pabeader]

klynne - I think you meant CC in that last post...

 

[engrav]

thank you; interesting

this AM fc5 cc0 pH7.7

is true the experiment was not a controlled experiment
but a controlled experiment would be painful
and finding penicillin was a fluke

today fc5 cc0 pH 7.7 so cc was probably 0 couple of days ago

I do get rather cavalier with bleach
if fc is low, I just dump in a gallon not checking PoolMath, I could easily have some “high” values

I think I like the ideas of
1) as per woodyp: some persons are more sensitive as biologic variation is enormous; wife can smell flowers a football field away whereas I must stick the flower up my nose
2) as per chemgeek: there is a clean bleach smell vs CC smell; sometimes when air is heavy and I bend down to get a sample I get a whiff of bleach even tho cc0 and pool outdoors
3) then as per both: person with sensitive smell churning the water and nose just out of the water could volatilize and smell a bit more “bleach”

I think I will stop just dumping a gal of bleach if fc a tad low; if suggested range is 2-6, add just enough to get to maybe 4; or maybe if fc is 3 and range is 2-6, don’t add any

but I suppose will have to check fc more often

thank you; interesting helpful

 

[chem geek]

See the post in the thread Chlorine Odor Question. You need to get out of your head that chlorine has no smell. Of course it does. When you smell concentrated bleach or chlorinating liquid you are smelling chlorine, not chloramines or Combined Chlorine (CC). It's just that in still water one normally doesn't smell the chlorine in the water unless one gets very close to the water with no wind. Churning of the water will increase the rate of chlorine outgassing.

A lower FC/CYA ratio will outgas less chlorine so will smell less under the same conditions of water movement and wind.

 

[engrav]

See the post in the thread Chlorine Odor Question. You need to get out of your head that chlorine has no smell. Of course it does. When you smell concentrated bleach or chlorinating liquid you are smelling chlorine, not chloramines or Combined Chlorine (CC). .

ah er, tis already out of my mind as I said
"I think I like the ideas of
2) as per chemgeek: there is a clean bleach smell vs CC smell; sometimes when air is heavy and I bend down to get a sample I get a whiff of bleach even tho cc0 and pool outdoors"

but not out of all minds as above I read
"fc has no smell but tc will stink you out of the POOL"

but odor post was interesting
quote
However, the above thresholds are for still water whereas churning the water to volatize the chlorine in the water can certainly get concentrations high enough in air that one can faintly smell the chlorine, mostly of hypochlorous acid.
quote
This business of "you can't smell chlorine" and "if you can smell chlorine, then it's really chloramine and you need to handle that in your pool" are extrapolated truths
quote
So too much chlorine isn't good either.
quote
Managing this using chlorine alone requires elevating the chlorine level at night when no one is in the pool

I think conclusion still holds, I should
1) cease mindlessly dumping a gal if fc low, be more precise, use PoolMath and then
2) add at night

thank you

 

[chem geek]

Well, the minimum FC/CYA ratio (7.5% for non-SWCG pools) that prevents algae growth is low enough that for most people they either don't notice the chlorine smell or it doesn't bother them. If you dose in the late afternoon or evening after you would be swimming or using the pool then the FC/CYA level will be lower during the day. If you really can't stand having the small level of chlorine smell you are having, then you'd have to use supplemental products to prevent algae growth and then target a lower FC/CYA level.

 

[engrav]

I think I understand
thank you, was helpful