how long can i keep these plants under this light??

hey you guys these plants are about 5 weeks old,, they are looking pretty healthy and are showing loads of nodes, they ae going to be nice plants.. but is this light good enough for veg.. it is 40 watt bulbs fluo... how long more should i veg and is this light gd enough???? thanks

You can grow them all the way until harvest under that light, but florescent lights cant the lower buds as well as a HID light, so the lower buds will be less dense.
so you could get some CFLS and place them around the bottom of them would help. greatly.

and you can flower the plants whenever you want, it depends on how big you want them to be, they normally double or triple in size when they flower