ok, I have a damn near unlimited supply of these 7 gal. trash cans (all new).. Would these be ok to grow in, all the way to harvest? Also, when I transplant, should I have the soil the plants are currently in wet or dry? peace

When transplanting soil in the pot being removed should be soaked until water is coming out of the drain holes. Than when its transplanted water the new soil too and you should be good.![]()
I have a bunch of those hydroton pebble thingies, should I throw an inch or so in the bottom?
You can if you want it won't hurt anything, I'd still get sme carbon though.
I'd also go with the rubber grommet and then you can get a 90 degree plumbing fixture and some clear tubing and tape it to the side of the can and if there is any water in the bottom you'll be able to see it in the tubing. I'd probably get a 3/8" or 1/2" grommet. Also if you need to drain it you can rotate the 90 degree plumbing fixture and let the water run out the tube.