So, not quite sure where to put this thread, but since the heading said "irrigation" I'll put it here. I plan to grow 18+ plants sog style in 2litre growbags in a tent. I don't want the worry and cost about setting up 18+ separate dripfeeds, so I plan to do it somewhat different. I use a very airy mix with only 50% soil and the rest coco and perlite (perhaps 5% vermiculite as well for some water retention). On the bottom of the grow bags I add those clay pebbles that you see hydro growers use. I then place the plants on trays where I also put the clay pebbles to give some room between bags and tray, plus clay pebble x clay pebble exposure since they are the airiest part in there. Early in the plants life cycle I let it dry out for a few days so it sends it's roots down looking for water, I then add some to the tray. So what I want is basically some easy auto watering system which will pump water in my trays on a timed schedule. Preferably so I can atleast leave the apartment 5-7 days and not be worried.