That's what I use, I do grind it up in the blender for the first week or so.I ended up getting 20% flock raiser instead of starter/grower. I hope that’s okay for the chicks. The person st TSC advised against chick grit for now so I didn’t get any to start.
They don't really need chick grit until you give them something other than chick feed or egg yolk, but it is good to give them some within the first few weeks, helps develop their gizzard muscles. I just sifted out smaller pieces out of a bag of regular grit that I got at the feed mill.
Here's a guide to sizes http://www.jupefeeds-sa.com/documents/GraniteGrit.pdf.
Do you have your MHP built?
Do you have your coop built?
If these are your first birds, you could skip the brooder phase

Have fun!!