Should the Chlorine stay stable overnight

May 29, 2007
6
Frostburg, MD
#1
Should my Chlorine level stay stable overnight? I am in the process of bringing it down after shocking after a new fill of my pool. Wednesday night numbers were:
FC 6.0
CC 0
PH 7.2
TA 80
CYA 28
Thursday morning numbers were:
FC 5.0
CC 0
PH 7.2
TA 80
CYA 28

I am trying to get to FC of 4.0 - 5.0 but want to make sure that everything is going right. I thought that with stabilizer in the level would stay constant overnight. It did from Tuesday night to Wednesday morning. We have had no swimmers as the weather here has turned cool but the water is crystal clear, shining and never looked better!! :lol: I don't want to do anything that will cause cloudiness now and may be having a problem with the Pool Owner Patience that I have read about. Please give me your thoughts!
 

Rangeball

Well-known member
May 25, 2007
785
#2
A 1 ppm drop overnight isn't bad at all. Some chlorine get's used up fighting organics that are continually introduced in the pool, like pollen, etc.

At this point I'd try to maintain the FC where you want it and as long as you stay ahead of things, you should have a very trouble free swim year ahead of you :)
 

Poseidon

Well-known member
May 24, 2007
148
Houston, Texas, USA
#4
kperkins,
Cyanuric acid protects chlorine from being destroyed by UV rays from the sun. Cya won't help chlorine hold overnight. Chlorine usage overnight would mean something other than sunlight is consuming it (as Rangeball said).