I show you how to build a vertical indicator light. Unlike TangoTek and MumboJumbo's Silo, this indicator works for only one double chest. It is fully customisable and is stackable, perfect for your farms.
TangoTek's Silo : http://www.youtube.com/watch?v=sZKj7kh_vwk
MumboJumbo's Silo : http://www.youtube.com/watch?v=EAJVmsPb4M4