Here is what you'll need to set up your system.
1 - 55 gallon food grade barrel (check craigslist*).
1 pump (I used a 200GPH pump I bought off of Amazon).
Grow Medium (Hydroton expanded clay grow pebbles or pea gravel is preferred).
1/2" piping for pump to beds, and siphon to tank (a 10' pipe is about $2 at the hardware store).
2 - #18 o-rings
2 - #14 o-rings
1 - 3/4" PVC pipe, 18" long.
2 - 3/4" 90° Elbow.
1 - 3/4" Male and Female threaded to slip adapter
1 - 3/4" to 1 1/2" Bell Adapter
1 - 2" PVC pipe, 8" long.
1 - 2" PVC pipe cap.
1 - 3" PVC pipe, 10" long.
anything to cut holes in plastic/PVC (I used a Dremel).
100% silicone and caulk gun
Other things you'll need:
Water Test Kit
empty soda bottle (for peeponics)
*neo71665 brought up a great point in the comments feed about buying barrels on craigslist and I wanted to expound on it here because I think its worth understanding. How do you know the barrel is indeed food grade safe? I myself buy from a person who sells food grade, and non food grade barrels of many different sizes including IBC totes. He receives them in mass quantities, cleans them up and resells them. If you can find someone who is doing this as a side business then I think you’ll find someone with a little more integrity than someone looking to make a quick buck for his personally used goods. Regardless of this I always do a smell test. Barrels used to store chemicals are a dead giveaway when you do the smell check. Most food grade barrels I’ve come across were used to store some kind of high fructose corn syrup and you can usually smell this if only faintly. Another dead giveaway is you may find dead bees inside the barrel, which have been attracted to the sweetness and got lost in the darkness (I see this often). Once you get your barrel home be sure to clean it out yourself just to be safe. If you're still worried about buying used barrels there's nothing wrong with buying them new.