These tubes are meant to give enough light to those boxes that are unfortunate to have been placed directly underneath the shelf.  I'm sure better lighting makes for better young plants, most of the split tubers here are 2006 seedlings. three at least are hopefully going to be sold by my good friend Bob Hendley and my mate Jack Gott, for my cancer charity Tenovus. So far we have the okay from Jonathan Ross, and await consent from no other than Darren Gough the Yorkshire and English cricketer, and Bob's favorite Fern Britton. The two neon strip lights are wired to the same plug, both are earthed to the casing, and both go through a time clock, which comes on at around five thirty at the moment, and goes off at midnight. As the evenings get lighter the timer is altered to suit.  Gradually the boxes of tubers are taken out, and replaced by freshly taken cuttings, and boxes of seedlings. Click back and see how  it illuminates the area compared to last year. Also essential to good growth.