New Member with High CYA, Low FC


New member
Jun 21, 2010
Hi all. I'm brand new to the forum, and also somewhat new to owning a pool. I'm in PA; pool details below. Been using a pool store in my area; anxious to get to BBB. Right now, I've been using A&S Super Pool Treat for shock, and tablets for maintenance. Ordered my test kit, but not here yet. My readings from the pool store:
FC = .1
CC = 1.4
TC = 1.5
pH = 7.6
Hardness = 210
Alk = 100
CYA = 125
So, I know my FC is low, and my CYA is high. Water is clear, but I get a little algae around the light. I've read through the info in Pool School, and the CYA/FC chart, but don't fully understand it yet. It says if my CYA is 125, then my target FC is 13.6, and my shock FC is 46.7. How do I convert that to necessary product (bleach) to add? Is the CYA so high, that I'll never get the FC up (and I have to empty some water)?
Thanks all,


LifeTime Supporter
Nov 18, 2009
Sacramento, CA
You can use the Pool Calculator to determine the amounts of chemicals. Setup the "Suggested Goal Levels" type (toward the bottom of the page), pool size (toward the top of the page), and "now" and "target" for each parameter.

You are correct in your interpretation of the CYA/Chlorine chart, but you really want to drain and refill about 2/3 before you head down this path. You already need to shock based on your CC level and shocking will be impossible with CYA that high.

Bama Rambler

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2009
SouthWest Alabama
With a CC of 1.4 you need to shock and with your shock level being 47 it's impractical to maintain that level. It would require 16 large (182oz) jugs of bleach just to get you there. And that's not counting how many to keep you there. Since reverse osmosis is not an option in PA, you need to drain about 2/3rds of your water.

But before you do anything drastic lets wait on your test kit and see what the results are with it.

Other Threads of Interest