FC burn rate?


LifeTime Supporter
Oct 26, 2010
15000 gallon fiberglass michigan

calcium 200
TA 80
PH 7.5
CYA 45

75 degrees 80% sun, what would be average ammount of FC loss by the sun for 1 day be?

water is crystal clear btw.

Bama Rambler

Mod Squad
LifeTime Supporter
TFP Expert
Jun 23, 2009
SouthWest Alabama
We usually try to get it down to about 2 ppm FC loss per day. Somewhere close to that is normal. With a CYA of 45 and in Mi you should be close to that.

If you're losing more than that, I'd suggest you run an OCLT to rule out organics eating it.


LifeTime Supporter
Platinum Supporter
TFP Expert
May 7, 2007
Silver Spring, MD
It is only possible to give you a rough estimate, as every pool is somewhat different. I would expect you to lose 40% to 65% of your starting FC level each day.


LifeTime Supporter
TFP Expert
Apr 27, 2012
Grand Rapids, MI
Smooth, I'm in Michigan, and although this is my first season, I have recorded my FC each day: Generally lose between 1.5 and 2.5 per day when I'm running FC 4-6 range for 45 ppm CYA -- depending it seems, on swimmer load and sun...And whether or not one allows a guest with a dog, which will land you on the -2.5 ppm side ;)

Most days, even the hottest ones like that scorcher Sunday of memorial weekend, I'm not using/losing more than 2 ppm, which is 33% of the 6 ppm at which I 'ride.' But I've also added 50 ppm borates, which buffers/reduces my chlorine load, and more importantly, makes water super silky feeling to swim in!