DannyD. wrote, on Wed, 25 Jun 2014 13:35:56 +0000:

The sun is brutal here, so I both add isocyanuric acid
(CYA) powder (not granules)

BTW, adding the special CYA *powder* is necessary under circumstances
when you can't run the equipment after having refilled the pool (due
to water levels taking weeks to rise given slow well refilling) and
given a very high sun load (California).

To be sure, adding the *powder* is easy, but all normal methods will
fail miserably, because once the powder gets wet, it *instantly* turns
into a solid brick! (I've never seen anything "set" so fast!)

Bearing in mind that CYA powder will do the same thing in your lungs, if
it ever gets that far, after a few failed experiments, I was able devise
a CYA powder distribution method that *easily* brings a pool from 0 ppm
CYA to about 40 ppm in a single sitting, with *no visible CYA residue*.

Here's a picture of the iso cyanuric acid powder:
https://c2.staticflickr.com/4/3754/1...f9945a46_b.jpg

Here's a picture of my starting point:
https://c1.staticflickr.com/3/2921/1...a42f6d2f_b.jpg

The first thing I did was sift the powder into a 5-gallon bucket of water:
https://c1.staticflickr.com/3/2935/1...49c388f9_b.jpg

If I didn't swish the water, and just let the CYA settle, this is
what happened at the bottom of the bucket:
https://c2.staticflickr.com/4/3774/1...1b2bb601_b.jpg

So, I learned to swish the water while shaking the powder over the
skimmer net into the bucket of water.
https://c2.staticflickr.com/4/3717/1...d6f33721_b.jpg

Then I poured the water into another bucket:
https://c1.staticflickr.com/3/2905/1...69793809_b.jpg

And, as I poured, I filtering out any sediment with a skimmer net:
https://c2.staticflickr.com/4/3714/1...6b420a5c_b.jpg

Over time, I learned, the more I swished, the less sediment I filtered:
https://c2.staticflickr.com/6/5191/1...0be45d05_b.jpg

Until I got to a point where four or five 8-ounce cups of the powder
would easily go into a five-gallon bucket of water:
https://c2.staticflickr.com/4/3665/1...6e28031d_b.jpg

Then, I simply poured the suspended-particle CYA "milk" slurry
into the pool:
https://c1.staticflickr.com/3/2901/1...c71a9dd0_b.jpg

The lovely clouds of suspended CYA particles in the water were
a beautiful sight to see (these clouds are *in* the water!):
https://c2.staticflickr.com/4/3799/1...6f8fb243_b.jpg

By way of failed experimentation, simply shaking the CYA powder
over the pool with a skimmer net fails if there is any wind,
as the powder blows away; and it fails the moment you accidently
get the powder wet (which turns it into an instant brick)
https://c2.staticflickr.com/4/3793/1...3920d46e_b.jpg

And, even if you're successful at shaking the powder over the pool
on a calm day, the powder floats on the top of the water like an
island, due to its propensity to form clumps:
https://c2.staticflickr.com/6/5113/1...9d55434f_b.jpg

But, I'm happy to report that the double-bucket swishing filter
method works just fine, and it's very easy and satisfying to do!
https://c2.staticflickr.com/6/5517/1...f36835bd_b.jpg

Here is another picture of the lovely cloud of CYA dispersing
throughout the pool, with each CYA particle surrounded by water:
https://c2.staticflickr.com/4/3723/1...931740a1_b.jpg

IMHO, this is the easiest, cheapest way, to add CYA to your pool
if you recently refilled it, and if you have a huge sun load, like
I do (which will murder you in chlorine costs otherwise):
https://c2.staticflickr.com/6/5571/1...f9853124_b.jpg