Can I let my FC Drop to "0"

[sangree99]

Moderator Note: Split off from this thread - Average bleach usage for season - Page 2

Your maximum usage, in the hottest summer months, will be about 3 ppm/day, when water temps dip below 60 degrees, it drops to zero, other months, in purgatory, could be figured at about the average of the two...

I've been following this thread because we just built our pool and I'm curious how much bleach I can expect to use. My water temp has been in the 40's to low 50's for the last month or two, but I'm still needing to add about 18 ounces of 8.25% bleach every two days in order to maintain FC at 4ppm (CYA is at 30, which I was told was ok in the winter). Is it really ok to let FC go to 0 when the water is cold? Or should I still maintain my target FC, just with the understanding that the FC loss will be much lower/slower in winter with cold water and less UV exposure. Any clarification appreciated. I don't want to be using chlorine and testing reagents if I don't have to. Thanks!

 

[tim5055]

Re: Average bleach usage for season

I've been following this thread because we just built our pool and I'm curious how much bleach I can expect to use. My water temp has been in the 40's to low 50's for the last month or two, but I'm still needing to add about 18 ounces of 8.25% bleach every two days in order to maintain FC at 4ppm (CYA is at 30, which I was told was ok in the winter). Is it really ok to let FC go to 0 when the water is cold? Or should I still maintain my target FC, just with the understanding that the FC loss will be much lower/slower in winter with cold water and less UV exposure. Any clarification appreciated. I don't want to be using chlorine and testing reagents if I don't have to. Thanks!

Is that air temperature? What is the water temperature?

Yes, once the water goes below 60 (not air temp) it is fairy safe to let the FC drop. Now, with that being said I feel it's worth the cost to keep adding bleach just for safety's sake. Figure your 18oz every two days is costing you about $7 a month. I think it's worth it myself.

 

[sangree99]

Re: Average bleach usage for season

Thanks for the response. That's water temperature. Air temps have been between high 20's and 60's. The water got down to mid 40's but is now back to 51 degrees. I think I'll keep doing what I've been doing since it's my first season, and next winter if conditions are similar I might just add the same amounts of bleach without doing as much testing.

Does that also mean less brushing is ok in winter? I suppose that while the algae risk is low, there IS still dust getting in the pool so it's probably still a good idea to get it off the sides/floor and into the water where it can be filtered out? I've been brushing once a week lately, but don't really notice much if any difference when I do.

 

[Patrick_B]

If you're running your pump a lot less often, brushing more often than you are would be prudent.