Chlorine smell after using blanket

jonmar

LifeTime Supporter
Jan 29, 2009
263
We haven't used the solar blanket all summer, but now it gets pretty cool at night, so it is on for a few days or even a week at a time. We haven't had any problems all year, keeping the chlorine at 40-45%. Why is it that once the cover goes on for any period of time the chlorine smell and burning eyes appear? Is it as simple as the sun is not burning off the old combined chlorine?
 

guamguy

LifeTime Supporter
Feb 26, 2010
388
Guam, USA
jonmar said:
Is it as simple as the sun is not burning off the old combined chlorine?
That's what I would suspect. Do you have test results? I would think you have some CC's in there.
 

duraleigh

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Apr 1, 2007
31,529
Sebring, Florida
Do you have test results? I would think you have some CC's in there.
Yep-er-doodle....I concur. :-D

If they aren't much (probably not). A little sunlight will help burn them off. So will elevated FC levels.
 

Bama Rambler

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Jun 22, 2009
22,964
SouthWest Alabama
The first place I'd start is by posting a full set of test results. You said "keeping the chlorine at 40-45%.". We don't measure chlorine in percent so that number bothers me a little.

While I suspect the same thing as the other posters we really need to see the big picture and test results will give us that.
 

jonmar

LifeTime Supporter
Jan 29, 2009
263
Bama Rambler said:
The first place I'd start is by posting a full set of test results. You said "keeping the chlorine at 40-45%.". We don't measure chlorine in percent so that number bothers me a little.

While I suspect the same thing as the other posters we really need to see the big picture and test results will give us that.
Sorry, the 40-45% is the number my salt system is set to. I use that all summer and never have any problems. The only time I get the smell is after the cover has been on. I'll try to do a test tonight.
 

jonmar

LifeTime Supporter
Jan 29, 2009
263
Haven't had a chance for the test. We had a real nice day today, so took the cover off this morning and jumped in after work. Problem solved, no stink. Is there some way to avoid the CC build up with the cover on? We are getting into much cooler temps these days and I expect the solar blanket to be on more than not. Is there some way to avoid a stinky pool for the 4-5 nice days left in the season?
 

Bama Rambler

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Jun 22, 2009
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SouthWest Alabama
Without test results it's hard for us to "guess" at what will solve your problem but with your lack of testing I suspect you're not keeping your FC high enough. Realize, that's just a SWAG since I don't know any numbers.
 

4JawChuck

Well-known member
Jun 13, 2010
223
Winnipeg, Manitoba, Canada
Without numbers its hard to suggest anything other than a shock of the pool which may not be required...get yourself a kit ASAP!

However I can suggest a good cleaning of the cover as a first start, dirt accumulates on it and the top can be a source of algae since it never sees chlorinated water. Clean the top off toward the skimmer with the hose and scrub with a brush to get the dirt out of the seams etc. Next submerge the cover with the long handle brush to get chlorinated water onto the surface to kill anything growing there but you may need to raise your FC up to take care of it and provide some FC overhead which your SWG may not be able to provide.

Did I mention you need a kit to test your water? You really can't do anything at this point until you know what you have for numbers. READ POOL SCHOOL! :-D
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,417
San Dimas, CA (LA County)
That happens to me, too. All summer long I wasted R-003, never got a CC reading. I put I cover on to keep the heat in, and the first time I tested after the cover was on, I got .5 CC. With cover pulled off to vacuum, CC disappeared the same day. And this is consistent.

So, like others have said, the chlorine is attacking the debris that still gets in the pool, forming combined chlorine, but their is no air flow and no UV to allow it to dissipate.

As long as the FC stays above minimum, I ain't worrying.
 

Ohm_Boy

TFP Expert
May 1, 2007
1,344
Orlando, FL
Just to reiterate... I'm sure you get tired of seeing all the "you need to post numbers" and "you need to test" posts.

Your salt generator is adding chlorine (free chlorine) to your pool constantly when running, and that may be sufficient for your pool, or may be too much, or not enough. You seem to have something in the pool which the free chlorine is attacking, and forming chloramines or combined chlorine (CC), but there is no way to know the eco-system in your pool without some real numbers. Maybe all you need is some sun. Or maybe you have a serious problem lurking in your water.
Your pool may even have a significant algae bloom, and the constant addition of FC via the SWG could be *just* holding it in check. That would be using up virtually all the chlorine being generated - an equilibrium. Algae doesn't become visible, FC doesn't stay in the pool. An overnight loss test reveals this. If this is the case, then you should elevate the FC level to shock target, and hold it there until no further overnight loss occurs.

Your target levels will be determined by the CYA (stabilizer) level of your water.

Without knowing SOMETHING about your water chemistry, we can only offer guidelines and guesses. Get us some test results, and we can tell you pretty much exactly what you have and need.
 

thepoolpros.com

In The Industry
Sep 9, 2010
12
coconut creek, florida
When combined chlorine is formed it will eventually off gas into the atmosphere, which is the chlorine smell. Whe you have a cover on the pool, it is preventing, or slowing down the provess.
By achieving Breakpoint chlorination will speed up the process of the offgas.
 

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