FC Loss overnight

[LookBehindYou]

Morning everyone. Is this something that should concern me? My FC last night was 3.5 and CC 0, this morning the FC was at 2.5 and CC at .5. The CC was within limits but I lost chlorine overnight. Do you think this something to be concerned about or is this normal? I added more bleach this morning to put at a FC of 5 (My CYA should be around 40, it was added as the pool was filling 2 days ago).

Thanks everyone!

 

[Charlie_R]

Was there anyone swimming yesterday evening before your test?

That is actually pretty normal. Some organics take a bit of time to be oxidized, so will show up like that.

 

[duraleigh]

A 1.0 loss of FC overnight is acceptable. Anything greater indicates the need to SLAM the pool.

You're OK except I would keep FC a tad bit higher so you don't go below the minimum of 3 ppm/CYA 40

 

[LookBehindYou]

Was there anyone swimming yesterday evening before your test?

That is actually pretty normal. Some organics take a bit of time to be oxidized, so will show up like that.

We were in the pool all day long right up until about a half hour before I tested it.

I did add enough bleach this morning to get back up to 5 FC.

 

[pwrstrk]

That's prob where you lost .5ppm. Not a big deal. You might want to shoot a tad higher in FC range if you get alot of sun and use.


Sent from my iPhone using Tapatalk.

 

[BoDarville]

You're good to go, as the others have stated. Worth reinforcing what others have said...FC should be increased a bit to allow for loss due to sunlight and normal disinfection. At a CYA of 40, you never want FC going below 3 ppm at any time. Recommend dosing chlorine in the evening after no more sunlight is hitting the pool. Try dosing FC to the mid-point of the recommended range (5 ppm) for a CYA of 40 to give you some headroom for normal daily FC loss.