Does adding borates and acid impact FC?

[dirty_steve]

I'm curious if the addition of all the acid and borates dropped my FC. My FC last night was 5.0 and it was also 5.0 this morning. After adding roughly 12 boxes of Borax and 3.5 gallons of acid, I just noticed that my FC is 0.5. These are the most recent test results and the only difference now is the FC is 0.5.

FC = 5.0 (usually around 3.0 with SWG, but added bleach b/c we had a bunch of kids in the pool)
CC - 0.0
pH = 7.4
TA = 70
CYA = 75
Salt = 3400
CH = 325
Borates = 50
Phosphates = 5,000
Jack's Seq-Quest = 12

 

[JasonLion]

No, raising borates doesn't normally have any impact on the current FC level. Long term borates should reduce your chlorine demand somewhat.

You don't normally lose any chlorine overnight, while you do normally lose FC during the day. Still, with a SWG and correct CYA level, that loss should be mostly replaced by the SWG.

I have no idea what happened. Do be sure to add some extra chlorine to get your FC level back up to normal.