I'm the same as you. I gave up smoking (hence growing weed) about 18 months back but still kept using my old low powered veg lights (250w) and 2x4 hydro table for growing other plants in a cupboard.
It tends to get used for tomato/cucumber/pepper/aubergine seedlings in to get an early start in spring for the garden and at the moment is mainly being used for a new experiment in 'bonchi', bonsai chilis. given enough light and warmth, chillis will fruit perpetually and respond well to scrogging (I have it set up as a U-scrog due to height/space restrictions). For peppers, I'm told you want flower nutes throughout.
I tend to germinate in soil in a heated propogator then wash roots and transplant straight into hydroton. If the plant is going into soil later, I simply pull it out, remove the clay balls, plant it, water in and feed a week later. Haven't lost one yet.
The only disappointment I have had is with Sweet Basil. I put this down to the ec of the res being too high for it. I still persevere with it though and have 3 single basil plants in there at the moment. It's not that they won't grow, it's just that they only grow at about the same rate as soil plants outside.
I recently grew a single GHS big bang in there for our birthdays and it looks like we will end up with a solid 6 oz (not finished drying and curing yet), whilst still producing stock for the garden.
Even for weed growers, why not utilise that wasted space in the canopy during early veg?
A $20 heated propogator and a South facing window or couple of cfls mean you can be germinating in the middle of winter and getting a good head-start to the season.