I read once in a book about aquariumlighting (I can search for the
title if somebody is interested) that the colournumbers (which are sold
by Philips), 82, 83 and 84 a little less, are the most efficient ones
for plant-growing. I think these colour-codes are only used by Philips,
so they're not interchangable between brands I think.
These are fluorescent tube lights, which are available in 60 cm and 120 cm.
Martin
Martin.Zevenbergen@algem.pt.wau.nl