Within the past 48hours, my FC has only dropped 2ppm. I have a CYA of 50 and it's been cool and cloudy for days. Is this normal? I usually have an FC loss of approx. 4ppm per day..depending on how hot it is.
Barely any FC Loss for 48hours/Is this normal???
- Thread starter Mendy48
- Start date
- May 3, 2014
- 62,730
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
Without organics, the only way you lose FC is to the UV from the sun. So if it has been completely cloudy, you have had minimal UV impact on your water.
Thanks for the info...yes! it's been completely cloudy and cool for days now...with minimal UV impact on my water. I feel at ease now. I just wanted to make sure.
A total of 4 ppm is sometimes normal in a pool, but going from 4 ppm to 1 ppm daily seems fine, if other variables have not changed.
Are you adding chlorine at the same time? Testing at the same time? Adding the same amount? If you are adding 2 ppm + daily, and loosing 1 ppm daily, your TC should have increased.
Are you adding chlorine at the same time? Testing at the same time? Adding the same amount? If you are adding 2 ppm + daily, and loosing 1 ppm daily, your TC should have increased.
I test my FC, CC and pH daily ... at the same time...every morning. I add chlorine everyday...same time (expect for a couple of days now being the there isn't much of an FC loss). The only variable that changed for me was the weather. It's been very cool and cloudy for days and like mknauss said, the only way to loose FC in a TFP maintained pool is via UV from the sun. I haven't had any sun for a couple of days which (by the way) is driving me bunkers. Nevertheless, all is good. I'll be having sun this week...all the way to the 90s this weekend, so I'm sure I'll be back to adding chlorine daily. I just wanted to make sure that my earlier post was normal being that it has been cloudy and cool for days.
How much chlorine do you add daily and what time exactly? And did you add any in the last 2 days? Important as chlorine additions when the sun is beating down is not a wise choice as a lot is lost to the sun. I always added mine before 7 a.m. and after 8 p.m. in the evening, which was rare. Even sometimes at 6:00 a.m. if the weather was going to be really hot.
Personally, I believe that this is too much of a disparity, even with the weather, but pools sometimes can be very different. Was there activity when there was a 4 ppm loss? This could also make a difference. I am not stating that this is abnormal, just trying to get a handle on why a larger spread.
At very high chlorine levels, you will consume more just because you loose a % and not a flat ppm daily. When my pool was at a CYA of 30, my FC loss was averaging 1.33 ppm weekly. When my levels are about 15 and I test, the loss daily is about 4 ppm, which some can be contributed to testing error.
There could be some items:
1) Testing Error (small, but almost common almost amongst everyone)
2) You had organics in your pool (small amount) and they were cleared up, thereby consuming more chlorine. Even though you test CC of "zero", there still could be something in your pool.
Although, at the end of the day, it really does not matter. Consuming less chlorine is a good thing. Consuming a lot more than normal shows signs of potential trouble. All good at the end of the day.
Cloudy and rainy here also, so I have only lost 2.5 or so over roughly 3 days (CYA of 50 here too) ... pools been covered with a solar cover those days until today. I lose between 1.5 to 2.5 normally, so it sounds about right! Enjoy 
Your post sounds totally fine to me. My FC usage drops way down if cool and cloudy and no sun.
Same here Mendy, cloudy,rain cool for 3 days. Only adding about 1/3 of chlorine that I would add on sunny warm days. Mid week upper 90’s will be swimming again !,
Add about 35-45oz per day at about 8am, daily (long before the sun starts to rise); I often add 1ppm above target; depending on how hot it's going to be.
I didn't add any in the last 2 days as I only lost 2ppm (cool, cloudy and some rain)
There was lots of activity when there was a 4ppm lost in my pool (but it was very very hot on those days, so the UV had something to do with that)
Water is crystal clear..beautiful oasis. I've often test for Overnight FC Loss Test (OCLT), and pass all 3 criteria beautifully. Yup... no chlorine loss is a good thing. I guess it's normal as many have experienced the same thing. As explained to me before, it make sense that if you don't have any organics in your pool and in addition to no UV impact, there will be minimal loss of FC in your pool. So I'm good.
I didn't add any in the last 2 days as I only lost 2ppm (cool, cloudy and some rain)
There was lots of activity when there was a 4ppm lost in my pool (but it was very very hot on those days, so the UV had something to do with that)
Water is crystal clear..beautiful oasis. I've often test for Overnight FC Loss Test (OCLT), and pass all 3 criteria beautifully. Yup... no chlorine loss is a good thing. I guess it's normal as many have experienced the same thing. As explained to me before, it make sense that if you don't have any organics in your pool and in addition to no UV impact, there will be minimal loss of FC in your pool. So I'm good.