CYA "poll"

[Rangeball]

Thanks for all the responses

I keep mine at 80-90. I live in a HOT climate, my pool is full sun all day, and I have a large swimmer load on a daily basis. If I try to keep mine lower, there's no way to keep up with the chlorine demand without taking a chance on an algae bloom.

Janet

Janet, Please correct me if I'm wrong.

I was under the impression that while stabilizer keeps chlorine in the pool, it prevents some of it from doing it's job and therefore more is needed to do the same sanitizing job as lower amounts in a low/no stabilizer pool.

For example, imagine after a party, 3 busboys (FC) start cleaning up. 2 drunken women wander back in (stabilizer) and grab two of the busboys and start dancing. There's still 3 busboys in the room, but only one is doing an work. Manager (pool owner) quickly sends 2 more busboys in to do the work, now there's 5 busboys in the room, but only the 3 are doing any work, the same as was getting done without the drunks.

If this is how it works, why is CYA even needed at all?

In the past before finding this forum, I like others ran a sky high CYA because the pool store wanted it that way. Now I know why...

I used bleach about 1/2 of last season, and closed it with bleach. This spring my CYA is low, about 20ish, and I'm maintaining FC between 3-5 ppm, and so far so good.

[Simmons99]

I think one of the "chemistry buffs" can explain this more technically that I can, but my understanding is that the CYA doesn't "tie-up" the free chlorine - if it did then it would change to combined chlorine (which is bad).

The CYA does inhibit the FC to do its job as well - so to add to your analogy- it would be two drunk women talking to the bus boy while he is cleaning - making him slower but able to stay around come AM - while the bus boy with out the drunk women (CYA) around would die like a vampire come first light.

If you have some CYA then you still have some chlorine working when it is sunny.

[waterbear]

I think one of the "chemistry buffs" can explain this more technically that I can, but my understanding is that the CYA doesn't "tie-up" the free chlorine - if it did then it would change to combined chlorine (which is bad).

The cya DOES tie up some of the FC and covert it to a class of 'combined chlorine' called chloramides which are stronger oxidizers and sanitizers than chloramines but not as strong as hypochlorous acid (FC). In the past sometimes anhydrous ammonia was used to help stabilize chlorine in pools by forming monochloramine, which is an effective sanitizer (Some mustard algae treatments today still depend on this chemisty).
www.usace.army.mil/publications/armytm/tm5-662/chap6.pdf has some interesting info on stabilization of chlorine.
(Chloramides are just a type of combined chlorine that will still test as FC with a test kit and still has some sanitizing ability but at a lower rate.) However, this form of combined chlorine is resistant to UV. At least this is how I understand it. Cyanuric acid is an ammonia/nitorgen compound with a ring structure .It is in a group of chemicals called triazines. (Does anyone recognize that from the full chemical name of trichlor or dichlor?) I am trying to find more info on the chemisty of this right now and can only find bits and pieces here and there.

[Wayne LaBanca]

I run 40 or so just because the group recommends 30-50. Interestingly, right now I am at 10, maybe, and seem to retain the cl the same as I was last year at 40. Same amount of sun but the heat is less. Is it the heat that leaches out the cl or the direct sun rays? I'm not going to add any Cya for a while to see what happens...

[geordie]

I am at 30-40 right now. I try to keep a puck a week in the floater to balance my ph which creeps up up up. I actually like the ph pretty high because the water feels better to me that way. However, I'm being much more careful this year because we are taking off for 10 days at the end of June so I need a margin for the CYA to rise with the pucks I will float while we are gone. Usually, with rain and backwashing I finish the season with CYA of about 50-60 and I have a very manageable bleach consumption the whole summer. I guess I am spending about $5 a week on chemicals on the average.

[tsandershsa]

For example, imagine after a party, 3 busboys (FC) start cleaning up. 2 drunken women wander back in (stabilizer) and grab two of the busboys and start dancing. There's still 3 busboys in the room, but only one is doing an work. Manager (pool owner) quickly sends 2 more busboys in to do the work, now there's 5 busboys in the room, but only the 3 are doing any work, the same as was getting done without the drunks.

You gotta love it!

[GHM]

The reason you need the drunken woman is because a busboy wouldn't be fun if life was all work and no play. As each busboy stop dancing he's happy and ready to work again. The drunken woman can then take a break, have another drink, and dance with the next busboy.
If there were no women the busbuys would work themselves to death. !

[aylad]

I was under the impression that while stabilizer keeps chlorine in the pool, it prevents some of it from doing it's job and therefore more is needed to do the same sanitizing job as lower amounts in a low/no stabilizer pool.

It is true that you must maintain more chlorine residual with a higher CYA--in your example, you start out with more busboys so that the drunken women tie up a smaller percentage of your help.

But the higher CYA also keeps the sun from consuming as much chlorine, which is needed in my case-- in straight sun for 100% of the day in daily temps ranging from 80-110, if the busboys have no shade, then there's nobody alive when the drunken women come around!

Janet

[Rangeball]

But if the drunken woman allow them to be counted but keep them from their work, what's the point?