salt is salt is salt, right?

Hey guys, I have been meaning to ask this question for a long time. I have seen several reports, posts, comments on using good salt in your water softener. What does that exactly mean?
I have looked in grocery, hardware, big box, and other kinds of stores to see what is for sale. I see the same choices.
Solar crystals, Salt Pellets, and Potassium pellets. Now I have read some info on the internet that crystals can bridge in the brine tank, pellets can mush in the brine tank and Potassium, well besides being about 12 bucks a bag and better health wise for you, will not be quite as effective as sodium regenerations.

So my question is what is cheap salt compared to GOOD salt. I personally use the solar crystals at about 4.75 a bag, and about every 3 weeks I'll do a little shakey shakey on the brine tank to unstick any bridging trying to happen.

 

I'm new here - I had heard that different systems require different types of salt to be used. Not sure if this is true or not....which leads to my question: I have a Culligan N8 Custom water softner and I'm not sure what type of salt I should get for it. Is there a difference? And if so which salt should I use for my Culligan?