First of the year adjustments Please help


Well-known member
Jul 16, 2007
37000 gal in ground vinyl lined 1 hp pump with cartridge filter

No chlorine so I didn't test for total/free The pool store is closed so I can't get chlorine till tomorrow
PH 7.8
TA 140
CYA off scale I filled the TF100 tube to the with the proper mixture and could see all the way to the top. I don't understand this. It was perferct at the end of the season. I don't use stabilized chlorine.

The water is clear and looks great. I don't have any trustable pool stores in this small town. I am hoping somebody here can help me get started. I will get chlorine tomorrow and shock tomorrow night so I can get some better chlorine numbers then. Could it be that the chlorine is affecting the CYA numbers?

Thanks ahead of time for helping. The smart people here bailed me out last summer when I fought an algae problem and the pool stores were taking me for a hundered bucks a week on chemicals that I didn't need.

I read a little more here and realized that the scale on the CYA tube is inverse. I had it backwars which makes complete sense now. How much cyanuric acid do you think I should start with?


Mod Squad
LifeTime Supporter
Platinum Supporter
TFP Expert
In The Industry
Apr 1, 2007
Sebring, Florida
Hi, Joe,

That's not an uncommon error...glad you sorted it out.

If it was my pool, I'd shoot for 40ppm of can always add a little more to say maybe 50-60 but start with 40 so you don't overshoot.

If you're gonna' shock, you may get a pretty good pressure rise and want to backwash. Don't backwash if you put the CYA in thru the skimmer for at least 4-5 days.


Well-known member
Jul 16, 2007
Thanks Dave,
I felt like an idiot. I have read quite a bit about the chemistry but I guess I didn't pay attention when I got the kit last summer because the CYA was good.
I forget the units that the store sells stabilizer in but I guess I will add one of the containers and take another measurement after a few days. I guess the CYA explains the chlorine also. It's really cool how all of these numbers are interactive.
All I did to the pool over the winter was shock it every month or so when I could tell it was about to turn green. The cartridge filter has really been a pain this spring though. It keeps cloggin up with pollen and the little worm things that oak trees put out. I think I will replace it with a sand filter this summer.
I love this site. The pools stores were killing me when I found it.