Shocking process... FC not coming down.

[thevodika4]

I started the shock process on Sunday. Our pool is a round AG 16x48 filled with well water. When I initially tested these were my results...
FC 0
PH 7.8
CYA 0
TA 210
CH 500
I used the pool calc. to make my adjustments and bring it up to shock level. I am now at
FC 12
PH 7.5
CYA 30
I am getting tons of iron and switching out filters and vaccuming every couple of hours but I still have a green tint to my water (lthough I CAN see the bottom. I would really like to get my sequestrant in but my FC has not gone down at all since Sunday night. My sequestrant reccomends adding it with a FC of 3. Is it normal for the FC to stay so high for so long?

 

[JasonLion]

In an outdoor pool, if CYA is really 30, than you should lose more than 50% of your chlorine each sunny day.

Again assuming you have an outdoor pool, something is very wrong with either your CYA measurement or your FC measurement.

 

[thevodika4]

Hmm, I'll test again. Could water temp have anything to do with it? It has not gotten above 70 (outdoor temp) since it has been filled.

 

[JasonLion]

Temperature has some effect, but it would need to be a lot colder than that to make a large difference.

 

[thevodika4]

You were right... CYA was at 60 (I think I tested last time too soon) and FC is down to a 7 today! My sequestrant says to put it in when FC is a 3 or less. What is your expert opinion? I am at my target FC level based on the Chlorine/CYA chart. Do you think I'm okay? Water is really clear today but still colored and still getting lots of iron on the bottom and in the filter.