[dmforcier]

Is dirt sterile? Plants grow in it just fine. The only reason I can see to sterilize is to kill off some bothersome pathogen. You got none of them, then don't worry about it. Use peat moss.

And remember what I said about the advice of garden center employees.

There's a Catch-22 with pot size. Too big and the won't all fit in your greenhouse. I go from starter cell to 3 1/2" pots, then up to 6" or so. But I'm winnowing the numbers as I go so I don't pot as many as I start. The 3 1/2" pots all fit under the lights. The bigger pots don't and go outside.

That's some decent looking dirt you got there. A little heavier on the perlite than I use, but definitely in the ballpark.

I'm interested to hear how the capillary cloth works.