I have been shocking my pool for over a week. I still am having 4-5 ppm chlorine loss overnight. I am getting tired of buying 12 bottles of bleach at a time. Shock level for our pool is 18. By morning I am down to 14 usually. Then I start the process over and add to get my level back up. Help! When is this going to stop?? Pool is crystal clear

Currently
FC 18
CC 0.5
Ph 7.5
CYA 60

Try increasing your shock level to 24, based on the Chlorine/CYA Chart in Pool School.

Also, have you brushed and checked behind light niches, ladders, and any sneaky place algae can hide?

With a CYA of 60 your shock level is actually 24 ppm. But it sounds like you are close. When shocking you need to maintain the shock level consistently or it will take longer. After the FC drops below shock level for your CYA it is not as effective and takes longer. If you need to walk away try and get the FC higher than 24, say 30 so you have some buffer.

I agree, bump your FC level a little over the shock level to give yourself some wiggle room. The harder you hit it and stay on top of it maintaining the shock level the faster the process will be. I went through the shock process earlier this year so a similar sized pool and it took over 2 weeks.

Hi brh,
My pool is way smaller, but was a mess when I started to clean it up the TFP way once I got my TF-100-XL kit.
Some of my problems were from the stock small filter cartridge not getting clear, but a lot was when the FC was falling below my shock value while at long work days, 9-10 hours.
One of the mods suggested to go 3 to 4 over my shock level to overcome my falling level when I was away.
That did the trick in the next 2-3 days, with a filter sock over the bucket skimmer!
Pool cleared right up and passed all 3 tests!
Hope this might help you. Oh, I also was reminded to have some POP! (pool owner patience)

Chuck