- Mar 5, 2020
- 3,221
- Pool Size
- 66000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V35
All the CYA I ever bought looked the same, no matter where I bought it - pool store, Aldi or Bunnings. I never questioned that it could look any different, and always assumed that this is what is called "granular" CYA here on TFP (to differentiate it from "liquid" CYA).
Even though I always noticed that, when applying the sock method, my CYA would instantly cake up to a brick-like consistency once wet. Left like that, it would probably take weeks to dissolve. I always gave my "brick in a sock" a good a knead with my hands, which would turn the brick back into individual grains, that would then pretty quickly flush through the sock and get dispersed in the pool water.
[EDIT]
As I said, the small grains will flush through the sock. You want to make sure that there are no accumulations on the pool bottom. I never had that problem, but depending on the coarseness of the sock fabric, how much squishing, pump speed, angle of the return eye-balls, general water circulation, pump speed, etc, that might occur. I only ever had a few grains settling on the floor, not in one pile, but quite evenly scattered, and with a brush stroke they all finally dispersed in the water. I also never added more than 10ppm worth of CYA at once, using two socks with 5ppm each (that's about as much as fits in the plastic cup that I put the sock in to make filling easier), one in front of each of my two returns. When trying this method, I would recommend to start small to see how your pool behaves, certainly don't add 80ppm worth all at once (I wouldn't recommend that anyway, that's a lot of acid). And definitely run your pump on high speed and keep it running until the sock is empty.
[END-EDIT]
When running my usual FC and pH test in the evening, I would see pretty much the expected drop in pH as calculated with Chem Geek's spreadsheet. Running a CYA test the next day (once I have enough sun shine) would show the expected rise in CYA. So far, so good.
Now I stumbled over an older post from Chem Geek:
And that made me think 'Hang on, is what I always thought to be "granular" CYA, actually "powdered" CYA?'. Which would make perfect sense, as it actually does look quite "powdery", and I always thought this would be stretching the definition of "granular".
And according to Chem Geek's post, this "powdered" CYA shouldn't be applied using the "sock method", but using the "swirling water in bucket" method. Or even better, avoided and replaced with granular CYA - which I have never seen in Australia (well, in the area of Melbourne I live in...). But as long as I give the sock a good knead to loosen up the "brick", I actually seem to be quite successful with the sock method.
The CYA that I always used (and until now considered to be "granular"), looks like that:
rhondachem.com
Well, turns out that the above is actually "powder", and when our friends from the US talk about "granular" CYA, they seem to be talking about this stuff:
rhondachem.com
Fellow-Aussies, what are your experiences, how does your CYA look like? And how do you add it to your pool?
Even though I always noticed that, when applying the sock method, my CYA would instantly cake up to a brick-like consistency once wet. Left like that, it would probably take weeks to dissolve. I always gave my "brick in a sock" a good a knead with my hands, which would turn the brick back into individual grains, that would then pretty quickly flush through the sock and get dispersed in the pool water.
[EDIT]
As I said, the small grains will flush through the sock. You want to make sure that there are no accumulations on the pool bottom. I never had that problem, but depending on the coarseness of the sock fabric, how much squishing, pump speed, angle of the return eye-balls, general water circulation, pump speed, etc, that might occur. I only ever had a few grains settling on the floor, not in one pile, but quite evenly scattered, and with a brush stroke they all finally dispersed in the water. I also never added more than 10ppm worth of CYA at once, using two socks with 5ppm each (that's about as much as fits in the plastic cup that I put the sock in to make filling easier), one in front of each of my two returns. When trying this method, I would recommend to start small to see how your pool behaves, certainly don't add 80ppm worth all at once (I wouldn't recommend that anyway, that's a lot of acid). And definitely run your pump on high speed and keep it running until the sock is empty.
[END-EDIT]
When running my usual FC and pH test in the evening, I would see pretty much the expected drop in pH as calculated with Chem Geek's spreadsheet. Running a CYA test the next day (once I have enough sun shine) would show the expected rise in CYA. So far, so good.
Now I stumbled over an older post from Chem Geek:
And that made me think 'Hang on, is what I always thought to be "granular" CYA, actually "powdered" CYA?'. Which would make perfect sense, as it actually does look quite "powdery", and I always thought this would be stretching the definition of "granular".
And according to Chem Geek's post, this "powdered" CYA shouldn't be applied using the "sock method", but using the "swirling water in bucket" method. Or even better, avoided and replaced with granular CYA - which I have never seen in Australia (well, in the area of Melbourne I live in...). But as long as I give the sock a good knead to loosen up the "brick", I actually seem to be quite successful with the sock method.
The CYA that I always used (and until now considered to be "granular"), looks like that:
Cyanuric Acid (CYA) Powder Granular, Swimming Pool Disinfectant, Sanitizer
Cyanuric acid or 1,3,5-triazine-2,4,6-triol is a chemical compound with the formula (CNOH)3. Like many industrially useful chemicals, this triazine has many synonyms. This white, odorless solid finds use as a precursor or a component of bleaches, disinfectants, and herbicides. In 1997, worldwide...
Well, turns out that the above is actually "powder", and when our friends from the US talk about "granular" CYA, they seem to be talking about this stuff:
Cyanuric Acid (CYA) Powder Granular, Swimming Pool Disinfectant, Sanitizer
Cyanuric acid or 1,3,5-triazine-2,4,6-triol is a chemical compound with the formula (CNOH)3. Like many industrially useful chemicals, this triazine has many synonyms. This white, odorless solid finds use as a precursor or a component of bleaches, disinfectants, and herbicides. In 1997, worldwide...
Fellow-Aussies, what are your experiences, how does your CYA look like? And how do you add it to your pool?
Last edited:
Every kind i have ever bought here in the US is definitely granules ( there is some powdery dust involved usually at the bottom of the container) This is good info to be aware of especially if it’s possibly the norm in Australia. There are quite a few posters from there on here.
