Strong Smell coming from Pool Cover

[elguillermo]

I have been having smell issues with a pool cover for over 2 years and I am looking for suggestions on what could be the cause.

I have an Inground pool (Chlorine) in Oakland, CA. For safety reason, the pool is covered using a vinyl/polymer cover from Poolcover Inc.
After 5 years, our first pool cover started to have a very strong and acrid smell of burnt plastic on hot days. The sales rep told us it was because the sun had attacked the cover and it was time to change it. Which we did. But 12 months later, on the new cover the smell is back.

I think it is something with the cover.
The vendor thinks it is something with the water, but the water is clear (no trace of algae) and ph is between 7.2 and 7.4

I have tried multiple things: washed the cover (though I could wash only the top), start using Pool Perfect enzyme (suggestion from the the cover vendor), algicide, slam to no avail. The smell is still here.

Would anyone have any hypothesis on what could be causing that smell?

 

[borjis]

How often do you let the pool breathe? (is it covered at all times)

do you have combined chlorine when you test?

My last inground pool got "smelly" at times when the cover was on 5 days in a row, but
I think that was combined chlorine from not being able to out gas.

 

[elguillermo]

In winter, obviously the cover is nearly always on. In summer though, the pool is open pretty much all day. When I close the cover at night, the smell is pretty atrocious. As if something from the water attaches to the cover. Could CC attach to the cover or would it stay only in the water?

Thanks

Guillaume

 

[JoyfulNoise]

I stopped using a cover a long time ago for many reasons, and cover cleanliness is one of them. If you drag the cover off the pool and roll it up somewhere, water will be trapped in and on the cover. The chlorine in that water will dissipate fairly rapidly and the moist environment will be ripe for bacterial growth. Anaerobic bacteria typically create some pretty putrid odors, so I would hazard a guess that your cover is just not clean.

What kind of test kit are you using to test your water with? Do you have some test results you can share?

 

[wjr75]

I have an auto cover but I don't get the heat from the sun that you get in CA. The cover probably is outgasing form the plastic material. The only other thing I would check is to make sure there is no standing water in the box that is rolls into. There is usually a drain but it may get clogged. Also when I clean the top of my cover I just get a bucket and scoop chlorinated water from the pool and throw it on the top of the cover and brush gently with my pool brush.

 

[elguillermo]

Thanks all for the response. Right now, from all the comments I have, I am running with 3 hypothesis:
1) smell comes from some sort of algae, bacteria
2) smell comes from high level of CC
3) smell comes from the cover itself
To test #1 & #2, I am going to slam the pool, but realized that I had a high level of CYA (100). So I am first trying to reduce it. Right now testing to see if Bio-Active Cyanuric Acid Reducer works.
For #3, we will replace the cover (negotiated with the vendor).

Also I have found high level of calcium hardness (570ppm) - could that be the cause of the problem?

Will let the forum know the results.

 

[wjr75]

We replaced our Coverstar cover a year ago but went with a Automatic Pool Cover , Inc replacement. It was about $1000 cheaper than Coverstar's.

 

[gtemkin]

Does your cover roll into an underground chamber? If so, does that chamber have a means to drain? Is it connected to the sewer system? Have little animals made a home down there (I had a rat living in my auto cover chamber, and for a while I couldn't figure out why the neighbor's cat would hang out in my back yard at that end of the pool, always crouched down in a wait and pounce position).