I recently purchased "Fast Dissolving Swimming Pool Stabilizer - Conditioner - Cyanuric Acid" from sinaindustries2016 on eBay (10 lbs for $26 delivered).
It was a very fine powder reminiscent of powdered boric acid (over which I prefer the granular). There were some clumps in the bag, which I did nothing about. I put a pound in a bucket with a couple gallons of pool water and attempted to stir. Initial results were discouraging as it seemed to settle in the bottom of the bucket. In for a penny, in for a pound I dumped the contents of the bucket plus two more pounds in the pool a started brushing it around. After only a cursory brushing I was encouraged: within a few minutes there was hardly any visible material left.
How long it will take to register on the CYA test remains to be seen, but it appears that I have an inexpensive (compared to liquid CYA) and easy method to add CYA quickly without messing around with a sock for a week.
It was a very fine powder reminiscent of powdered boric acid (over which I prefer the granular). There were some clumps in the bag, which I did nothing about. I put a pound in a bucket with a couple gallons of pool water and attempted to stir. Initial results were discouraging as it seemed to settle in the bottom of the bucket. In for a penny, in for a pound I dumped the contents of the bucket plus two more pounds in the pool a started brushing it around. After only a cursory brushing I was encouraged: within a few minutes there was hardly any visible material left.
How long it will take to register on the CYA test remains to be seen, but it appears that I have an inexpensive (compared to liquid CYA) and easy method to add CYA quickly without messing around with a sock for a week.