Step 15: Installation and Rationale
Using the downspout adapter, multiple barrels can be linked together. Some people design their rain barrels with the downspout adapters at the bottom. The downspout adapter is placed at the top of the barrel in order to allow one barrel to completely fill up before filling the next one. This creates the water pressure that will push water through your hose.
I do not use a screen in my barrels because I designed a closed system rain barrel that will prohibit mosquitos from entering the barrel once everything is hooked up properly. You can clean the barrel by turning it over and spraying it with a hose. If you need a screen, you can cut out a piece of window screen and sandwich it between your barrel and your downspout.