I'd bet it is dolomitic lime. I wouldn't hesitate to use it as the Ca component of your soils, E. You could also use gypsum, and that doesn't change soil Ph.

Al

Thanks. that should make me sleep better. i dont know why I ask now when I have already planted more than 50 containers. I was just counting because now I am undertaking drip irrigation. I plan on using the 7gph sprayers so it just doesnt drip out. Hope it will work.

Good luck, E. I know you'll fare well. ;o)

Al