Darren,
My plants had only been sprouted for 3 days indoors, when i put them under my 400w hps, I just kept the light well above the plants for the first few days ( a good 3 ft up) & then gradually bring it down closer over a few more days to them, until u get the right temp at plant height.

MNSN
mrnotsonice Reviewed by mrnotsonice on . changing lights how big should i let my plants get under the fluro before putting it under my 400w hps light,(they have only just sprouted). :eek: Rating: 5