PSA - All dry CYA is not equal

[Brett S]

So yesterday I discovered that my CYA was quite low (probably because I’ve had a ton of rain recently) and I needed to add some. I had a bit of HTH brand CYA on hand, but only about half as much as I needed. I put a bit more than a pound of the HTH CYA in a sock yesterday morning. Within an hour or so it had become pretty mushy and I was able to squeeze the sock every 30 or 60 minutes or so and got it all dissolved into the water within a few hours.

I also ordered more CYA yesterday morning and unfortunately Amazon was out of the HTH brand, so I ordered the Pool Mate brand instead. It arrived yesterday afternoon (gotta love Amazon same day shipping). I put a bit more than a pound of that into the same sock and it’s taking forever to dissolve. I squeezed it a number of times yesterday evening before I went to bed and started again this morning after I woke up. At this point the Pool Mate CYA has been in the sock in the water for nearly 18 hours and it is still feeling quite granular and not mushy at all. It is slowly dissolving, but probably at least 75% of it is still in the sock.

The HTH brand was so much quicker and easier to dissolve.

 

[PoolNewb2020]

What is the size of the granules of the pool mate vs HTH?
I used Pool Time stabilizer from HD and that one turned mush in the sock pretty quickly as well, but I noticed the granules were quite small, compared to the CYA granules my PB used when starting up my pool for the first time. He "dissolved" them in a bucked and just dumped in the deep end. They were in my pump basket for several days before going into the filter.

 

[goonerbilt]

I used Chlorox stabilizer and 3lbs. dissolved in the sock (placed in front of return jet) in less than 30 minutes I ended up having to brush my pool floor ever 30 minutes for hours just to make sure it wasn't sitting on my liner at the bottom. Pool was dark green so I couldn't see if it was there and I didn't want to vacuum it into the filter. Not doing that again!

 

[Brett S]

They were both pretty small. I can’t really compare them because I used up all the HTH before the Pool Mate arrived, but as I recall there wasn’t much of a difference. The Pool Mate might be slightly larger, but not significantly.