Added Calcium Chloride and FC dropped

[aggie.band.79]

Numbers yesterday
FC - 3.5
CC - .5
TC - 4.0
PH - 7.6
TA - 60
CH - 220
CYA - 5 or less

Bought a 15 lb. bucket of Leslie's Hardness Plus and added 10~12 lbs. last night (plan was to check before adding the rest)
Product was "dry broadcast" over the entire pool area, with highest additions at the deep end.

This morning Chlorine is at ZERO. Probably 12 to 13 hours later.
I checked, and there was no sun out last night.

Today's Numbers
FC - 0
CC -0
TC - 0
PH - 7.6
TA - 60
CH - 290
CYA - 5 or less

 

[ajw22]

This morning Chlorine is at ZERO. Probably 12 to 13 hours later.

We hear that happens after adding calcium. We do not have an explanation for it.

Get your FC back up to target using liquid chlorine.

Your CYA is too low.

What Are My Ideal Pool Levels?

Use our tool to find ideal chemical levels for any swimming pool. Check TFP recommended levels on pH, free chlorine, cyanuric acid, and more.

www.troublefreepool.com

 

[aggie.band.79]

Numbers yesterday
FC - 3.5
CC - .5
TC - 4.0
PH - 7.6
TA - 60
CH - 220
CYA - 5 or less

Bought a 15 lb. bucket of Leslie's Hardness Plus and added 10~12 lbs. last night (plan was to check before adding the rest)
Product was "dry broadcast" over the entire pool area, with highest additions at the deep end.

This morning Chlorine is at ZERO. Probably 12 to 13 hours later.
I checked, and there was no sun out last night.

Today's Numbers
FC - 0
CC -0
TC - 0
PH - 7.6
TA - 60
CH - 290
CYA - 5 or less

Just added 1 gallon of Chlorine
Will check again in about an hour

Yes, I know I need to get my CYA up, but that would not have mattered last night.

Recent history:
Pump was leaking - took it apart - no one had the parts (all of the parts) to rebuild it.
I had to order them so I was down about a week there.
Parts came in and I rebuilt the pump.
Pump ran great - no leaks - but now I had a leak at the flat gasket on one of the bulkhead fittings.
Again - no parts - no one seemed interested - ordered myself.
While waiting on parts I deep cleaned my sand (because sand never goes bad)
Also on a whim, I decided to paint my filter - looks really nice.
So, during this time I was down maybe 3 weeks, and the green set in.
Probably should have at least kept adding Chlorine, but I did not.
Everything has been running almost 2 weeks now - Water is back blue, but not completely clear and sparkling yet.

 

[JJ_Tex]

There have been others who reported similar experiences when adding Calcium. We have never been able to pinpoint why or identify a common theme amongst products. The actual calcium should not have any impact on your chlorine, but the leading theory is that sometimes the manufacturing process includes impurities not included on the label and that is what killed the chlorine.

Long story short, you are not alone, we don't know why it happens sometimes, you handled it correctly by testing and immediately adding chlorine.

Once you get your chlorine back in range, I would also suggest an OCLT since you mentioned your water had been green and is not yet sparkling. That will tell you if you indeed have algae and need to complete the SLAM to kill all algae.