Film on water under auto cover

akropp

Active member
Dec 2, 2018
43
Tarrytown/NY
My pool for the most part has been very clean and clear thanks to following the TFP way, however I have noticed that whenever I open the cover, there is a film on the surface of the water that looks like it could be algae (or something else?). I tried to capture it in some pictures. It goes away after the cover has been open for 5-10 minutes, and there are no other signs of algae in the pool.

Any ideas what this could be and how i can get rid of it? I am guessing that there is a film of algae or something on the bottom of the cover, but it seems that even high FC doesn’t do anything to it.
 

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Rocket J Squirrel

Silver Supporter
Bronze Supporter
Jun 7, 2018
1,009
Alamo, CA
Pool Size
36000
Surface
Plaster
Chlorine
Liquid Chlorine
I see this sometimes after opening my auto-cover. Not every time, and not as bad as what you see. I have a strange theory about it. I think maybe it's the pigment of the cover coming off into the water. I think this because I see the aqua color of my cover on my filter cartridges when I clean them, and also on the exposed styrofoam of my skimmer weir doors. You would think an item designed to be in constant contact with water would not leach into the water, but perhaps the higher-than-industry-standard FC levels of TFP cause this. So I try to keep my FC & CYA toward the low end of the TFP range, which is fine with a mostly covered pool.
 

akropp

Active member
Dec 2, 2018
43
Tarrytown/NY
I had that thought. It is also sometimes accompanied by a turpentine-like smell. I haven’t found any reference to that — not sure whether is it some algae thing or possible as you said the cover reacting to the chlorine.
 

JamesW

TFP Expert
Mar 2, 2011
21,972
Is your cover pump leaking oil?

If oil is getting on top of the cover, it will transfer to the bottom of the cover when the cover is retracted and rolled up.

The oil will transfer to the water when the cover is closed.
 

cowboycasey

Gold Supporter
LifeTime Supporter
TFP Guide
Jul 3, 2013
4,740
Fletcher, OK
that looks like some kind of oil, suntan lotion/oil? can you roll your cover out and put dawn dish soap on it and then spray it off with a hose spray nozzle... it will not hurt the pool, I put at least 2 cups in a season to kill boatman bugs and I also do this on my own bubble cover to clean it.... I also clean the skimmer with a sponge in the soapy water... :) Matter of fact I should do it today... (y)
 

akropp

Active member
Dec 2, 2018
43
Tarrytown/NY
that looks like some kind of oil, suntan lotion/oil? can you roll your cover out and put dawn dish soap on it and then spray it off with a hose spray nozzle... it will not hurt the pool, I put at least 2 cups in a season to kill boatman bugs and I also do this on my own bubble cover to clean it.... I also clean the skimmer with a sponge in the soapy water... :) Matter of fact I should do it today... (y)
Could be. It definitely looks a bit like oil. Not sure what the smell is though. I feel like I need to somehow clean/scrub the bottom of the cover, but I’m not quite sure how to do that. Break out the scuba gear? 😉