We recently found a great link to anyone interested in Rain Barrels http://www.aquabarrel.com
This Company has a great website on Rain Barrels and you can hook up our products to the hose faucet coming off the bottom of the barrels.
This is what you need to set up a Drip System off a Rain Barrel that will gravity feed the water to the plants:
Filter (MLFF-41): 1/2" Poly Faucet Fitting (MLF-33): 50ft of 1/2" Poly (MLT-71): 1 or 2 packs of 90 Quarter Circle Misters (MLM-03B): End Crimper (MLA-50) or End Fitting (MLF-ENDCAP): Punch Tool (MLA-51) or All-in-One Tool (MLA-TOOL).
Your first question maybe why would you want to use a 90 Mister to drip water?!
Reason is that with gravity feeding off the rain barrel there is not enough water pressure to run the Drippers properly yet with this Mister the water drips out nicely. You will only get about .5 up t 2 gph dripping out of Mister depending on rain barrel height.
To install just attach the Filter to the faucet off the rain barrel, then thread on the Faucet Fitting, push on the 1/2" Poly, lock down the collar, run the 1/2" Poly through your garden, punch a hole in the poly where you want to drip water using your punch tool, then thread the 90 Mister directly into the Poly Tubing and lastly attach the end fitting. Typically we were able to put up to 25 of these 90 Misters around plants using up to 50ft of our 1/2" Poly Tubing. If you want to get more elaborate and use a pump then you will have more options of using our Drippers and/or Micro Spray Stake Assemblies. Check out Aquabarrel site for more rain barrel information or feel free to email us!
Have a great day!