Water barrel System connections and overflow

Fun with water barrels!

So the next step in the roof rain collection has happened - I bought the barrels.
The first steps:
1. figuring out where to put them
2. figuring out how many I would need
3. finding clean, food grade barrels for a reasonable cost
4. getting them delivered

The 275 gallon tanks ($125 each) will eventually have some sort of fencing in front of them -- probably bamboo -  and shade cloth over the top to prevent growth inside the tanks. Water from the roof will run through PVC along the fence into the tanks.

The smaller 55-gallon tanks ($20 each) will be set close to the house
 on blocks with a single access point either from a rain chain or downspout.

Here are some links for sites that have been helpful in putting together my water collection plan:
(I am not necessarily going to use these exact plans - I will post what I use)
https://www.youtube.com/watch?v=MYTNciCplmw

https://www.youtube.com/watch?v=GUhox1ORlRk&feature=related

http://www.instructables.com/id/DIY-275-Gallon-Rainwater-Collection/?ALLSTEPS

http://www.irrigationtutorials.com/drip-gravity.htm

http://www.dripirrigation.com/drip_irrigation_chapters/25/drip_irrigation_pages/40