Hi Bro, I always alternate sunlight and artificial light at beginning and for all seedlings stage. My girls seem to love this. CFL bulbs work on for 1/2 weeks. This year I've bought on AE some interesting led lamps for less than 20 bucks, 28W (declared) full spectrum, E27. These are visible on my new diaries so U can judge if they work or not alternated to sunlight. Remember the rule "not less than 15000 lumen". Cheers