Instructions / Info Sheets   Articles   Web Links   Glossary of Terms   Frequently Asked Questions Web Links Below are some links to external articles related to greenhouse lighting. If you come across a term you don't understand, check our Grow Light Glossary for an explanation. Providing Long Days By Erik Runkle - GPN Magazine Cyclic Long-Day Lighting - Beamflicker By Erik Runkle - GPN Magazine The Benefits Of Lighted Plugs By Erik Runkle - GPN Magazine Maximizing Supplemental Lighting By Erik Runkle Strategies for Supplemental Lighting By Erik Runkle Daily Light Integral Defined by Erik Runkle, Greenhouse Product News