Should I increase my CYA level?


Bronze Supporter
LifeTime Supporter
Oct 6, 2009
I was just re-reading Jason's sticky article on BBB for Beginners, and based on some info in the CYA section was wondering if maybe I should increase my CYA level a bit.

I'm considering installing a Liquidator next year, as the process of adding a jug or two of liquid bleach to the pool every day is getting old. But I'm also wondering if perhaps increasing my CYA slightly for now will lessen the chlorine demand a bit.

My CYA level currently runs around 50-60 (actually it's been dropping a bit lately - most likely due to splashout and backwashes). I've been using a target FC level of 7 and pretty good about getting enough bleach in each night to get it up to that level. There is no overnight chlorine loss, and my CC level is almost always at zero. The next night when I test, my FC levels are typically in the 3.5 to 4.5 range (an FC loss of about 3.5ppm daily). I attribute this to the direct sunlight the pool receives all day long (no shade at all).

In reading Jason's article, he mentions that if you have a SWG (which I do not) or get extreme amounts of direct sunlight on the pool (which I do), you should maintain a CYA level between 60 and 80.

I'm on the low end of that scale, so I was thinking that bumping my CYA level up to 70 or even 80 might allow me to benefit from a lower daily chlorine demand, because of that much extra stabilization of the chlorine. Am I correct on this assumption?

I also realize the increase CYA level puts me at a higher Target FC level as well, but once there, I'm wondering if the extra CYA will keep it at that level a bit longer, so I don't use so much bleach every day.


P.S. Current levels are:
FC - 7
CC - 0
TC - 7
pH - 7.6
TA - 90
CH - 220
CYA - 50



I'd leave it. I get full sun all day as well, and hold 6-7 ppm with my Liquidator, and CYA at 40.

It's harder to get rid of CYA than add it, and you are on the high end already. If it were me, I'd wait until the LQ was installed (if you go that route) and play with your CYA then, if needed.


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
Raising the CYA level will indeed mean adding less chlorine each day, but it will also make things much more difficult should you ever get algae.

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