Ca/Alk/Mag Mess . . . How to fix?

[Aquattro]

Originally Posted by Enigma

It is a new bag of salt. That makes me a bit nervous, as it could be quite different from the previous bucket.

Honestly, it's just salt. As long as it's the same brand as what you've been using, you're good. Mix it up for an hour, if it mixes clear, that's my sign that salt is good.
If you're still concerned, do a quick alk test. You don't need to knead the bag, or flip it, or mix for 24 hours. Mix it in RO, let it go clear and hit a close temp to what you need, and change water. It's just a water change.