daug,
Congrats on changing to swg! We're about 10 years down the road from you. My wife noticed the same thing back when we were in our 60's so I tried salt... she was very skeptical but tolerated a trial with just salt before I finished installing the swg. Within 10 minutes she exclaimed "This is great! I never want anything other than swg again". Skip a little less then 10 years down the road to today. We just installed a new OB pool in the house I OB'd two years ago. With new plaster we haven't started up the salt system for the recommended 30 days but that's definitely next. She can't wait and neither can I. I was also shocked that we already have 1000 ppm salt and I guess it's due to a very high chlorine demand from our kind of nasty well water. The water has cleared up nicely though and I get the robot this Saturday finally! Even with the 1000 ppm salt starting point I'm gonna need 15 bags +/- and I dread lugging this to the pool.
As to the salt type, I've used all kinds and they all work fine. Some of the brands seem to have a little more dirt and sand than others but that cleans up quickly. This doesn't seem to correlate to price. I also have a water softener and I use a LOT of salt in it. I've tried a lot of different brands and found the salt bin gets a nasty brown foam on top for all brands except very few. My thinking is that less dirt is better and may be an indicator of less harmful minerals but who knows? One of the best I've found is at Tractor Supply and it looks like this. So far no muck build up at all and others have this happen from just a few bags:
View attachment 593873
I haven't tried Morton's brand because it doesn't come in a large crystal (not important to pools but prevents bridging in my water softener). I think they'll also deliver it for free! Now that's a priceless advantage for old backs!
I hope this is helpful.
Chris