CYA testing/adding troubles

Amama

Member
Jun 19, 2017
22
Holden, MO
We just recently got our pool filled for the summer after having to buy a liner and new pump.

I added CYA aiming for a level of 30 last week, and found out I was out of CYA reagent, so got it today, and it was close to being measured, but I filled the tester as full as I could and the black dot was very cloudy but not gone. I poured it back into the dispenser and tried again, but had the same results. How do I know how much more stabilizer to add, should I assume it's around 20?

Free chlorine was ok for a day or two, then has been 0 every time even with adding 2 qts at night.

Water is clear still.

FC - 0
pH - 8.2 (having trouble keeping it down just like last year)
CYA - 20?

Thanks
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
32,592
Laughlin, NV
I suggest you add 20 ppm more CYA powder.

Add the CYA by using what we call the sock method. Get an old sock (no holes) and put the measured amount of CYA you need. Tie the sock closed and either suspend it in front of a return (hang it from your brush pole works with something weighted on the deck) OR if it still allows flow thru the skimmer, place the sock in the skimmer. Every 15/20 minutes give the sock a squeeze to speed up the process. Please DO NOT follow the directions on the container of CYA to just pour it into the skimmer and don't just toss the sock in the pool as the CYA is acidic and can bleach/stain pool finishes.

Assume your CYA is now 50 ppm and use the [FC/CYA][/FC/CYA] to determine FC level needed. Use the Target level. Add liquid chlorine every day.
 

Amama

Member
Jun 19, 2017
22
Holden, MO
Thank you, yes I do use the sock method as I read about it on here last year and didn't want to damage our skimmer/filter.

I'll try the 20 ppm more.

I was aiming for a lower level of CYA (30ppm) so I wouldn't have to use as much bleach.

Thanks
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
18,795
Bedford, TX
I was aiming for a lower level of CYA (30ppm) so I wouldn't have to use as much bleach.

Thanks

A,

While the FC target level has to be higher with a higher CYA, you actually need less bleach.. As the CYA increases, the amount of FC burned off by the sun decreases.. So it might take a little more bleach to get up to the target level, but once there, it should take way less bleach each day to maintain that level..

I too would shoot for a CYA of 40 or 50 ppm..

Thanks for posting,

Jim R.