CYA Levels

[SJohnson]

Everyone should read "WATER CHEMISTRY FOR SWIMMING POOLS"

Here's a link:
http://www.deh.enr.state.nc.us/ehs/chem.htm#ta
There's also a chart on that page that will show you how much certain amounts of cyanuric acid will raise your CYA levels. I've found it handy to keep a printed copy of this information lying around . . . Many people advise dissolving CYA in a sock(pantyhose) placed in skimmer . . .

Also, there was an article by PoolDoc(Ben) on the advantages of high CYA levels, which was interesting but I can't remember if that was on the forum or in poolsolutions . . . anyone remember where that was?

CYA exerpt from "WATER CHEMISTRY FOR SWIMMING POOLS":

"Stabilizer - Cyanuric Acid
Hypochlorous acid is a highly unstable molecule which dissipates rapidly in the presence of sunlight. This results in considerable loss of free chlorine from pools exposed to sunlight. Proper stabilization of chlorine with cyanuric acid slows the rate of chlorine dissipation without appreciably sacrificing oxidation and disinfection activity. Reaction of free chlorine with cyanuric acid produces a form of combined chlorine (chlorimide) which is active enough to aid disinfection and show up as free chlorine residual on your test kit. Proper stabilization requires 30 to 50 ppm cyanuric acid. Outdoor pools should be initially treated with 40 ppm cyanuric acid.

Cyanuric acid dissolves very slowly and is best predissolved in warm water before introducing into the pool. If it is not predissolved it may take several days to dissolve completely. Once added to the pool, cyanuric acid does not dissipate. It is removed from the pool only by splash out and backwash waste. Stabilized chlorine products such as trichloroisocyanuric acid will add stabilizer to the pool and may cause a gradual rise in cyanuric acid concentration. Excessive amounts of cyanuric acid can interfere with the disinfection process and at concentrations above 100 ppm may cause "chlorine lock" and clouding of the pool. Cyanuric acid level is lowered by draining part of the water out of the pool and diluting the remaining water with fresh water. Generally cyanuric acid level should be kept below 60 ppm. Stabilized forms of chlorine should not be used for superchlorination because cyanuric acid level may be increased. "

[Watermom]

SJohnson wrote:
"Cyanuric acid dissolves very slowly and is best predissolved in warm water before introducing into the pool. If it is not predissolved it may take several days to dissolve completely."

I have not found this to be true. CYA will not just dissolve quickly even in warm water. It will still take awhile. Don't worry about it. Just pour it in through the skimmer while the pump is running. Then, don't test for it, backwash or add more for about a week to be sure you give it time for all of it to dissolve. It is better to add it gradually and sneak up on your target rather than try and hit it in one dose. Be patient and you can get the level where you want it to be.

Watermom

[SJohnson]

That's in the quote from the "WATER CHEMISTRY FOR SWIMMING POOLS". I actually have always used the panty hose method, and have never tried dissolving it in warm water . . .

SJohnson