Hi Tracy, Each product at Home Depot that you'll find on the webpages of the main site here, should display the current amount in stock at the store that you choose all the way in the upper left of the screen. In many cases, you can have the product shipped to your residence or held at the store for pickup at your convenience.
I couldn't tell you why, maybe computer glitch.
It's just coarse.
Yes, it works quite well. Like any salt product, it is less effective below a certain temperature. But generally if you remove the bulk of snow to get to the base frozen layer, and apply generously the salt, it will re-liquify the frozen ice through the chemical action. Sunshine and above 15 deg farenheit it does quite well. Take care on concrete, do not overapply. Sweep it off once the ice has melted. But I've never had any issues on a concrete porch.
I use it in mine
Water softener helps
No it’s a home water filtration system
I don't know the cost, but at Home Depot, there is a price break if you buy 6 bags.