Now that my greenhouse is finally complete, I have been experimenting with an automatic
S/H watering system (see photos below).
I was able to use 1/4 inch tubing with the help of a sizable water pump. I have adjustable
flow rate knobs in each line so vary the amount of water to each pot (this takes a little
time to get right).
I pump water from a 55 gal barrel of RO water through a Dosatron injector and then out
to the plants.
My plant tables are 6' x 3' and I can comfortably place 40-50 small-medium plants per
table or 30 larger plants per table.
I set up the tables as "zones" for watering and can water each table/zone in less than
two minutes.
Ray commented that I should replace the galvanized pipe connected to the pump
with plastic pipe as the carbonic acid formed from carbon dioxide
dissolving in the water will corrode metal pretty aggressively, even though
it's a relatively mild acid.
I will post an update once I have the system working for a while.