Thanx for all of your input. I started this grow as a "learning curve, catching up on technology" grow. I haven't grown any in over 25 years, probably closer to 35.
I intend to compost, am putting in a reverse osmosis system, and a 25 gal nalgene chemical storage tank w/floating lid to store pH correct water, and Nute solution, all this for the next "real" grow.
I have had success with this grow beyond what I expected.
So, looks like I'll be saving all the shells and bags for future use. Question, if I start a compost pile now, would it be advantageous to mix that compost in my next soil? What constitutes a good compost? I'd really like to stay 100% organic next grow. I am sticking with soil. less to go wrong for me.