FC problems...can't seem to fix

[schulze4512]

Pool was doing great on the BBB method. Now for the last week it will not hold chlorine. I have shocked it repeatedly but when I check in a few hours, it has dropped 1/2 or more of the FC. I have crystal clear water but I don't like testing in the morning and having an FC of 0. Forgot to add, have been shocking to a level of 10 to 12. (following chart)

Any ideas or suggestions?

Here are my levels as of 4pm today:

FC 4.5
CC 1.0 (was a .5 until I had to repeatedly shock)
PH 7.4
ALK 150 (has gone up since shocking, was 125)
CH 225
CYA 15-20 (this has not changed much)

using a Taylor K-2006 to do the testing.

We are pretty high temps this week but this started before the high temps got here.
Thanks for any help. I am cleaning the store out of bleach trying to keep up with my FC.

 

[linen]

Shocking is a process, and not just the act of putting chlorine in your pool. You need to hold your FC up at the shock level until you pass all three criteria in the shocking process.

 

[woodyp]

Your CC of 1.0 indicates you didn't finish shocking properly. Add enough CYA to take your level to 30 to start and shock at that level.

 

[jblizzle]

Does not sound like you are exactly following the shocking process. Are you testing hourly and maintaining the FC at shock level?

Are you loosing a lot of your FC overnight when the sun is not out? Do the OCLT to determine if something is living in the pool.

Since your CYA is so low, you are likely loosing a LOT of your FC to the sun during the day.

My recommendations:
1. Raise CYA up to at least 30ppm.
2. Raise FC to shock level and do an OCLT
3. If you have a loss overnight, go through the shock process (might should do this anyway since you have a CC > 0.5ppm)

 

[wetchem]

Have you read: How to Shock Your Pool... it's a process not a product. Set aside some time to do this.... it will take time... it will take effort... it will take patience....

With the CC at 1 and constaintly loosing FC it sounds like you've a monster trying to grow.
You need to get the FC up to shock level and keep it there, or slightly higher, keep adding bleach as often as nessary to keep the FC at the shock level... also get a brush and brush down the sides of your pool and the bottom... until you stop losing FC per the instructions in poolschool.

-wc

[edit] Wow... I need to type faster :!: [edit]

 

[schulze4512]

Thanks for the help. added bleach and tested all afternoon and evening to keep the level up. This morning, pool had only lost 1ppm of FC and my CC is .2 . Water is still clear. What I love the most about BBB is the fact that I never lost the pool to green. This is the first year since we had the pool put in that I can stay on top of it before it goes to a swamp. :-D :-D I will continue to test all day today to watch my levels. I will find CYA at one of the pool stores to raise it up. I love Pool School!

 

[chem geek]

CYA 15-20 (this has not changed much)

If your pool is exposed to sunlight, it will lose quite a lot of chlorine during the day at this low CYA level, probably losing 90% or more of the chlorine. With no CYA at all, half is lost every hour, but with only 15-20 ppm FC you still lose perhaps 20% per hour. Is there any particular reason why you don't have the CYA at least at 30 ppm if not 40-50 ppm?

 

[dweebs0r]

I was having the same problem as you, losing a ton of chlorine during the day. Not really being able to keep up with the chlorine use. My problem was that I had depleted my cya to almost nothing. I have been doing the BBB method for the last 2 years and this was the first time I have had this happen. I literally had 20 jugs of bleach sitting by the trash can at one point. The solution for me was to go to the pool store and purchase chlorine stabilizer (which is just cya) and add it to the pool. Now I have a higher cya level and have to maintain higher chlorine levels but I am not adding 2 large containers of bleach to the pool every day to keep up.

 

[schulze4512]

"I literally had 20 jugs of bleach sitting by the trash can at one point" LOL this is exactly what my recycling looked like! Low CYA is definitely my problem...that and a very high swimmer load everyday with this heat. I am replacing a lot of water. I added CYA to my sock in the skimmer. Thanks so much for all the help! I haven't been to the pool store all year!!!! How great is that?!