florescence is your problem IMO. you need atleast an HPS bulb to get a decent yield from all i have read of autos. florescence bulbs should be used for about 3-4 weeks of growth then switched.
Go to your local wal-mart or shopping center and grab a 5$ bottle of plant feed you will be glad you did. But however Yes you will still get bud worthy to smoke with just water. Ive always used nutrients though.
if its at 50 days you aint got long till it starts to die of on you, you will need to start flushing soon i suggest next time round you get proper lights and nutrients and you will pull a lot more than just a couple of grams
50 days looks like you have another 40 it only looks like its 2 weeks into flower planter is too small and auto's like dry soil dont get me wrong they need water just dont like to sit in it when i started to figure out what a auto needed my veg growth doubled and yields followed most auto's run 10 weeks alot of the higher yielding auto's can very easily go 12 weeks
and on the cfl comment i get good yields from cfl's but i run a lil over 400 watts true watts of mixed spec and this plant isnt going to just die off on any given day it has to run a full cycle if its growth is slowed by lack of light or over watering then its going to take longer to run that cycle