Dropping 4-5 FC a day

merc123

Bronze Supporter
Aug 2, 2019
67
Georgia
I’ve seen it on various pool websites. I did see a 1.5 PPM of FC Also.

Right now I’m consistently at 40 ounces every night after the sun goes down. It ends up at between 3-4 FC at the end of the day. Doesn’t matter if anyone swims or not.
 

kellyfair

Gold Supporter
Bronze Supporter
Jun 29, 2016
2,686
Tampa, FL
Check your CYA one more time... you are adding to first line, glancing, still see dot? Add to second line, glancing, and so on?
 

kellyfair

Gold Supporter
Bronze Supporter
Jun 29, 2016
2,686
Tampa, FL
For a 7600 gallon pool, with CYA 50, it would take 39 ounces of chlorine to go from 3 FC to 7 FC.

To slow down chlorine loss you could bump CYA but I would first make sure of the current number, doing test as above in full sunlight, sun behind you.
 

JW1

Well-known member
Sep 4, 2019
159
SW Ohio
For a 7600 gallon pool, with CYA 50, it would take 39 ounces of chlorine to go from 3 FC to 7 FC.

To slow down chlorine loss you could bump CYA but I would first make sure of the current number, doing test as above in full sunlight, sun behind you.
Is that correct? I’m getting 31 ounces unless I’m inputting incorrectly.
 

merc123

Bronze Supporter
Aug 2, 2019
67
Georgia
Doing the CYA test in sunlight and not in the kitchen I'm at just a little under 50. I'm at 2.5 FC right now. According to the app to get 7 FC I need to add 37 ounces. 40 ounces would be 7.3.

I have double checked my pool volume by measuring the height of the water itself and still around 6500 gallons.
 
Last edited:

Oly

Gold Supporter
Jun 28, 2017
1,542
Fresno, CA
I know you said that your overnight FC loss is minimal but I have to ask, do you have a ladder in your pool?
The pool ladder I used when I had an AGP was designed to allow water inside and was an algae breeding ground.
Just a thought.
 

merc123

Bronze Supporter
Aug 2, 2019
67
Georgia
I know you said that your overnight FC loss is minimal but I have to ask, do you have a ladder in your pool?
The pool ladder I used when I had an AGP was designed to allow water inside and was an algae breeding ground.
Just a thought.
We take it out nightly for safety.
 

Oly

Gold Supporter
Jun 28, 2017
1,542
Fresno, CA
If it is hollow then check the insides closely, it may be the source of your FC loss and pulling it out at night would explain the low overnight FC loss.
 

merc123

Bronze Supporter
Aug 2, 2019
67
Georgia
If it is hollow then check the insides closely, it may be the source of your FC loss and pulling it out at night would explain the low overnight FC loss.
That is a possibility. I thought of that after I typed we pull it out at night. It definitely lets water into it.
 
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Rattus Suffocatus

Silver Supporter
Jun 5, 2019
1,047
Corona de Tucson, AZ
If you cover the pool when not in use it'll drop to about 2-3 PPM/day FC loss. But 4-5 uncovered in the mid 80's is completely normal. As much as I hate the cover that is why I do it. That and minimizing evaporation which here in the dry desert cools the water down quite a bit and then it's refilled with higher TA water, CH rises... etc... everything in a pool is a tradeoff....
 

merc123

Bronze Supporter
Aug 2, 2019
67
Georgia
I added 40 ounces at 12:21. I just checked FC at 12:50 and it's at 9.5 from 2.5. Based on that kind of math my pool would be 4500 gallons which is quite a difference.
 

merc123

Bronze Supporter
Aug 2, 2019
67
Georgia
If you cover the pool when not in use it'll drop to about 2-3 PPM/day FC loss. But 4-5 uncovered in the mid 80's is completely normal. As much as I hate the cover that is why I do it. That and minimizing evaporation which here in the dry desert cools the water down quite a bit and then it's refilled with higher TA water, CH rises... etc... everything in a pool is a tradeoff....
That makes sense. I just wanted to make sure I wasn't doing something ridiculous.
 

merc123

Bronze Supporter
Aug 2, 2019
67
Georgia
I was. We went on vacation so I threw in the duck with 3-pucks of 4-in-1 and put a cover on. When we got back (10 days later) it was at 26. Uncovered it and vacuumed. Next day it was down to 12.5 and 7 the next day. I removed the ducky so it would naturally drop. I did drill drain holes in my ladder and I think that’s a source of the usage. It had some nastiness in the ladder. So we’ll definitely remove it unless we are in the pool.
 

merc123

Bronze Supporter
Aug 2, 2019
67
Georgia
So since using the HTH 3” tabs in the floating ducky I’ve had a consistent 5-6 FC levels. I’m going to watch CYA but this may be a better solution for me than liquid chlorine. I can dump water to lower CYA and water isn’t costly to refill.