Balancing water with solar cover

[ekadd]

Hi all, I use a solar cover/blanket during spring and fall which I started using 1 or 2 years ago. For the first handful of years with our pool (without the blanket), keeping the water in balance was super easy for me. I'm not sure the science behind it, but I notice that when I put the cover on, I have been struggling to keep the water in balance. The issue seems to be with keeping the chlorine level up. This surprises me as I expected with no sun light on the water that the opposite might happen with the chlorine.

With the cover on, i know i need to test the water more often as a start, but can anyone give me some insight into what having the cover on does to the water balance as that will help me understand what is likely going on.

Thanks!

 

[PoolStored]

The only thing the cover will do is retain heat, lower FC consumption and slow pH rise. Should do nothing that increases FC usage, unless you live in the south, when the cover would raise the temperature high enough to consume more FC and CYA. Not your problem in Toronto.

Post a full set of chemical results. Likely not the cover, likely algae...because FC got too low. Or, your CYA is low. What do you normally run your CYA? What is it now?