FC in Winter

[Guest]

This is my first "winter" in Georgia with a pool. I am planning on keeping the pool open - I have a freeze protection thermostat on my pump so it automatically comes on when the air temp goes below 38 degrees. I have a question regarding chlorine levels: My pool water is down to 55 degrees. I am not covering the pool. Do I still need to keep the FC level at 3ppm (recommended troublefreepool.com) all the time? I have read that algae cannot start in water below 60 degrees, and if that's the case can't I just start adding bleach in the Spring when the water temp starts coming back up?

 

[BBBliever]

Below 60 algae is slowed but will grow. FC consumption will drop dramatically. You can probably get by adding chlorine once a week or so. The other option is to let it go to the algae and deal with it in the spring.

 

[chem geek]

While algae growth rates slow down, so does the chlorine killing/oxidizing rate. You need to maintain roughly the same FC/CYA ratio as you normally would, but it is true that algae growth is quite slow when the water is colder. When my pool water gets to the 50-55ºF range, I only need to add chlorine once every week or two. That's with a pool cover. If your pool is exposed to sunlight, you can still have chlorine loss from that since it's independent of temperature, but usually in the winter there are more days with less sun and the sun is lower in the sky so less intense.