Quote Originally Posted by Sprocket View Post
I forget who told me to take the cover off for a bit every day or longer if going for more days without the cover off .

Something about gas lock , anyone join in and correct me . But it seems if the pool doesn't breath a bit from time to time , the gases lockup and it won't let your FC work like it should .

Sooo even if it's cold out I try and get the cover off for a 2 hours or so every other day .

Hope this helps ya and gl .
I've got plenty of evidence it's a myth, but I wouldn't swear to it.

Our pool's at our place-in-the-country-soon-to-be-our-primary-residence. For two years now I've kept the solar blanket (cut to fit) on for the couple weeks between visits and suffered no algae blooms, nor any other contamination. At first I did have something which turned out to be my ignorance of the reaction of Cl, iron-rich water and sunlight. But all last year I never opened the cover and had to do much more than vacuum a bit and add some Cl. The cover would have been on for two to three weeks at a time. And the pump was timed to run two periods of four hours each day.