Cooler Weather, FC - 3 days no change?

Sunbaby

LifeTime Supporter
Feb 27, 2015
1,397
Centerville, TX
Pool Size
15000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Jandy Truclear / Ei
Hey guys - it has been a while since I have posted (which in pool land means all is well). I have been on bleach for a while - everything going great. It has gotten chilly here in TX - my pool water is at 60 degrees - right now it is 55 out. Up until this past week - I have been adding 30-35 ounces of Bleach a day. (I test, use pool math, but this is the norm). The past 3 days - my FC has remained at 9 - I haven't added anything. I know it slows during the colder months - but could this be right? Everything else is testing fine according to pool math - all within range.

I am just worried that maybe I am missing something??
 
I've dialed my SWG back to 15% and FC still drifting up, so will back it down to 5%. Water temp at 59 degrees and falling.

My first winter, I didn't know any better and kept the SWG at my usual 50%...saw my FC inexplicably rise practically to SLAM levels until I realized the cold water and short daylight hours impact on pool chlorine consumption. Turned off the SWG - it wasn't until the spring that my FC got back down to normal levels.
 
I'm in Kingwood Texas about 30 min away from you in Conroe and I'm going through 27 ounces every day with a 19K pool. And I have been for the past month. I have been testing daily too.
 
Sooo weird! I'm at 8 today. But haven't added bleach. I keep thinking what if my chemicals are bad but my water looks perfect.
 
still trying to figure out all the numbers. Tested pool yesterday, water 46 , fc 1.58 total chlorine 2.13, combined 0.55, ph 7.4, hardness 540 which seems very high, cya45 swg has been removed for one month now. using a chlorine floater with large disks alk 87 should I be worried tried pool math yesterday but was confusing to me
 
If your fc is 1.5 and your stabilizer 45 you are at risk of algae. Not sure what kit you are using to get ppm readings to the hundredths. At the bottom of pool math, set your reference for trouble-free.com, put your test results in the left column for all readings. If your results are not at or near the recommended levels, the section to the right tells you what to do.

But you should start in poolschool at the top of these pages, and get a recommended kit.
 

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Sunbaby, and despite my post a couple of days ago I too am noticing that my FC is holding. I'm down to just adding a little less than 13 ounces each day. I have a Stenner hooked up to my ET8 so I'm just making the adjustment in my schedule. Once it stabilizes for more I will probably unhook the Stenner and bring it in and just to a week chlorine dosage.
 
yep that time of year...my water is now at 42 and soon it won't need any bleach added to maintain until spring.

my last pool needed nothing added from Dec until mid march.

Won't you still lose some to the sun?

My temperature dropped from 60F to 50F this week and that's about as low as it goes here and I still lost 1.5/2ppm in 6 days. I get sun pretty much all year round so I'd imagine I'm looking at that sort of ppm loss until spring (but maybe I need to give it another week or two of solid 50F to be sure). How are you able to avoid the sun eating up your chlorine if you don't have a cover? This is my first TFP Winter/Spring so I'm curious to see what my chlorine costs will be.
 
Yup,

We get quite a bit less UV this time of year, even though the sun may be shining. Its the UV that eats the chlorine.

UV is a bit lower in wintertime because we are farther away from the sun. The farther UV has to travel, the weaker it is when it gets to us. So lower UV = less FC loss. And add to that, there are all sorts of things in the atmosphere that can filter out some UV. And generally, the atmosphere is pretty active in wintertime.

Also during warmer water temps, our FC is constantly fighiting off algae spores that multiply in our pools and that consumes some FC.
With the colder water temps help with slowing down the FC consumption because the algae spores are much less active.
 
I live in So Cal and my current pool temp is 50 degrees. Last July and August I was adding (via a Stenner pump) 64 Oz per day to keep my FC at 6-7. It has been pretty cool here lately (for So CAl) and my current Chlorine demand is 13 Oz to keep the same FC. Quite a difference!
 
Won't you still lose some to the sun?

My temperature dropped from 60F to 50F this week and that's about as low as it goes here and I still lost 1.5/2ppm in 6 days. I get sun pretty much all year round so I'd imagine I'm looking at that sort of ppm loss until spring (but maybe I need to give it another week or two of solid 50F to be sure). How are you able to avoid the sun eating up your chlorine if you don't have a cover? This is my first TFP Winter/Spring so I'm curious to see what my chlorine costs will be.

I might lose just a few ppm due to sun over the ENTIRE winter, but also the way my backyard is to the south sun and the foliage blocking, I get less direct
sun in the winter. During the winter months the sun is lower in the sky as Divin Dave said. That and gray skies over the fall/winter are much more common than sunny days.

It get's cold here in the winter...average temp is upper 30's lower 40's....but this past (this is rare before december) week my pool surface has been frozen..about 1/4 inch thick, though the water in the skimmer is not frozen.
 
Yup,

We get quite a bit less UV this time of year, even though the sun may be shining. Its the UV that eats the chlorine.

UV is a bit lower in wintertime because we are farther away from the sun. The farther UV has to travel, the weaker it is when it gets to us. So lower UV = less FC loss. And add to that, there are all sorts of things in the atmosphere that can filter out some UV. And generally, the atmosphere is pretty active in wintertime.

Also during warmer water temps, our FC is constantly fighiting off algae spores that multiply in our pools and that consumes some FC.
With the colder water temps help with slowing down the FC consumption because the algae spores are much less active.

In the Northern hemisphere we are actually closer to the sun in the winter - you aren't trying to say Texas is in the Southern Hemisphere are you:eek: The sun angle and UV index is lower in the winter due to us being tilted away from the sun.
 
In the Northern hemisphere we are actually closer to the sun in the winter - you aren't trying to say Texas is in the Southern Hemisphere are you:eek: The sun angle and UV index is lower in the winter due to us being tilted away from the sun.

The whole earth, not just the northern hemisphere, is about 3 million miles closer to the sun in early January than in early July.

In the winter the northern hemisphere is not getting hit by the sun as directly as we are in the summer.
 

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