I can't seem to keep a FC level above 1.0.

[Watermom]

Your pH is fine. Don't worry about it.

Like I told you before, I think you are on the verge of an algae bloom and that is why you can't hold a chlorine reading. You are letting your chlorine levels drop too low. With a CYA of 50ppm, your chlorine needs to stay between 3-6 all the time. Dip below that and algae will start. Did you ever shock your pool as I suggested above? If not, you need to or you will never get past this and at some point, the pool will probably turn green. Your shock level will be 15ppm. http://pool9.net/cl-cya/

In your pool, each quart (32 oz) of 8.25% bleach will add about 1.5ppm of chlorine. Each of the 121-oz jugs will add about 5.7ppm. Test your pool and add enough bleach to take your chlorine up to about 15. You need to continue to add enough bleach to stay at shock level until three things occur:
1) You can go from sundown one evening to within an hour or sunrise the next day without losing more than 1ppm of FC overnight.
2) You have no greater than 0.5ppm of CC
3) Your pool is clear.

[reesie]

Yes, we shocked it. We added 3 gallons of 8.25% bleach at 6 am the morning (7/16) after I read your post. That evening the readings were
fc 9.0
cc 0
ph 7.8
alk 90

Tonight (7/17) readings were

fc 4.5
cc 0
ph 7.6-7.8
alk. 90

We have been keeping it between 5-7ppm until the last week when I started having this problem.


I'm sorry, I didn't realize I need to keep it at shock level so I didn't add more bleach since it was still at 9fc with no cc last night. I tested tonight

[Watermom]

Ok. Test it this evening and go ahead and add enough bleach to get back up to shock level. Until you can hold a chlorine reading overnight without losing more than 1ppm of FC, continue to shock the pool daily. Once you pass the overnight test, we typically suggest keeping the chlorine high for one additional day for added insurance and then you can let your chlorine drift down. (By the way, it is best to shock the pool in the evening. Then, an hour or two later, test your chlorine so you'll have a reading to compare to the next morning.)

Keep us posted how things are going.

(No need to test alk every day unless your pH starts bouncing around. As long as pH is stable, testing alk once every week or two is fine.)

[reesie]

Thanks!

Once again, you guys are the best! I wish I had found you guys when we first bought our pool in '93. We wouldn't have gone with Baquacil and had that nightmare of an experience. You guys got us through the conversion and it's been great since. ..well a few hiccups but y'all always help me through it.

Thanks for the tips. I usually shock/add all chemicals at night but ran out of bleach and had to wait for store to open to buy more this time. I didn't know I don't have to test alkalinity every time. I've been testing ph and alkalinity every time, but not CYA.

I just tested.

fc 7.0
cc 0

I'm taking it back to shock level and will test again in 2 hours as suggested, then first thing in the morning.

Thanks!