Sometimes people who are new to rain water collection are concerned about roof runoff, leaves and mosquito larvae collecting in the barrel. Green Planet Rain Barrels specifically installs a screen filter in every barrel we sell to prevent this from happening. While not necessary, you can also join your barrels together using a connection kit (we call it Daisy-chaining). Daisy-chaining two or more barrels together acts a lot like the ground does by filtering the water even further with each stage it flows through, as the silt and residue that accumulates in the first barrel does not overflow into the second. Any accumulating in the second does not flow into the third, etc and the water keeps getting more filtered.