CYA Cost.....did I just take it in the keester?

[BigDave]

I can't read the label in Leslie's picture. What does it say exactly?

[columbusdan]

Monosodium cyanurate monohydrate - 35%
Percentage of constituents ineffective as spray adjuvants - 65%

[BigDave]

Oh, new to me. Maybe someone else knows what it is and how it reacts. Here's the patent in Google http://www.google.com/patents/CA2246208C

[PoolDoc]

It's an easy but expensive way to add CYA.

An easier -- and cheaper -- way to do so is simply to add dichlor till you get there. Though it doesn't seem to quite make sense, dichlor is 1/2 CYA by weight. In other words, you could label dichlor as 50% strength CYA -- making it MUCH stronger than "Instant Conditioner".

Here are the Instant Conditioner instructions:

Directions for use:
Instant Pool Water Conditioner

One gallons of Instant Pool Water Conditioner will raise the conditioner/stabilizer level in 10,000 gallons (38,000L) of water by 32ppm. The recommended minimum conditioner/stabilizer level necessary to stabilize chlorine from sunlight loss is 30ppm.

Dosage for fresh water start-up (no conditioner/stabilizer present):

Divide pool volume in gallons by 10,000 gallons to determine the number of gallons of Instant Pool Water Conditioner required
SHAKE WELL!
With circulation pump running, pour Instant Pool Water Conditioner into pool skimmer slowly OR pour directly into pool water, while walking around perimeter of the pool. Brush to speed absorption
Rinse container with pool water and shake
Pour remaining rinse solution into skimmer or pool


Maintenance Dosage:

Measure CYA level in pool using cyanuric acid test or have it tested by a professional pool products supplier
If CYA level is less than 30ppm, calculate gallons of Instant Pool Water Conditioner needed using the following formula:

4oz added to 10,000 gallons = 1ppm increase of conditioner/stabilizer level

Note that 1 gallon will raise the CYA level 10,000 gallons by 32 ppm. And also notice that a gallon costs $37+ at Leslies.

So, what will $37 of dichlor do? At Sams Club, 50# of dichlor is $105, so $37 equals 17 lbs of dichlor. But 17lbs of dichlor will raise the CYA level in that SAME 10k gal pool by 100 ppm -- 3x as much.

In other words, as a CYA source, dichlor is 1/3 the cost of Instant Conditioner . . . even without considering the value of the chlorine it adds!

[columbusdan]

That makes sense, but I have a follow-up question. Once I reach the ppm I want to be at w/ the CYA, do I have to stop using the dichlor so that my CYA won't go any higher? If so, what eventually makes the CYA come down so that I can use more of that? Just don't want to buy that much dichlor and not be able to use it once my CYA is at a proper level.

[Watermom]

Once your CYA is where you want it, you can switch to using bleach. CYA levels pretty much stay the same all season. Some pools lose the CYA over the winter and have to add it again the next year.