since you asked this, and I see some other more experienced growers are logging their grows on Gnomo here, but I thought I'd reply.
I'm in week 8 going on 9 of a gnomo grow. Guess I'd say I'm intermediate so far as experience goes. This is the first time I've used non-bagseed. I have had a couple of grows produce some reasonable quantity but they hermed out on me. Still got a bit of halfway decent smoke and cannabutter out of it but didn't seem worth the effort and worry.
I got 5 fem'd seeds of the gnomo and every one popped in 24hrs and turned out female, more than I was expecting so I've got my hands full now
The genetics don't seem to be quite consistent but I can't complain. Three came out as very vertical with strong central stems. One started out with a nice little pyramidial habit and we thought she would be the superstar. The fifth, or "runt", looked like an aberration; seemingly weeks behind the others in growth, although looking at it under high magnif. it was growing ok and even showed tiny female hairs not long behind the others. These girlies showed sex in like 2 weeks from seed I think. (haven't been logging it real close)
I didn't bother with trying to train these. They have stayed very short and I don't think I'll be forced to mvoe them to a bigger cabinet before they're done.
Got weird about week 6. Started seeing problems at leaf tips and brown blotches on the leaves, on the 3 vertical ones and then a different looking leaf issue on the pyramid type. Adjusted the nutes according to the soil tests and the 3 verticals have improved but still don't look super-healthy, while the pyramid looks pretty tragic but keeps developing, if slowly. The verticals don't have many fan leaves at all. The "runt" meanwhile looks awesome (in the 5 and 8-9wk group pics pics she is back row center). I think some types in this gene pool are kinda picky and/or sickly. But most are budding up like crazy.
They've been on 20/4 with a high-output 110w fluoro fixture on veg spectrum plus two LED 14w sidelights this whole time. Going to change the tubes out to the warm spectrum set this evening. I've put it off because the Runt was still a little behind but I really don't think it's strictly necessary to change bulbs or even short the light period for the autos, though I hope the bulb change will help them finish up sooner. The trichs are becoming less clear now, I think. I expect I'll start giving them only water pretty soon.
Growing these in foxfarm ocean soil and feeding with foxfarm grow big, with a little here and there of ff open sesame, ff big bloom, maxicrop seaweed, superthrive, organic humic acid soil tonic, and epsom. started off using distilled water but am now mostly just using 2-stage filtered water in one of those gallon Pur dispensers.
So, you might not have a great experience if you just start one seed, since it's not a super-consistent strain yet, and you might end up with one of the really picky ones. But I've been pretty impressed so far.
I was considering taking a test snip today but instead took the least-budded little sprig from the bottom of Runt and trimmed it off to see if I could re-veg one little clone (yes, I know it's late in the game and maybe autos can't even be re-veged, just thought I'd try one). I trimmed off the tiny budding areas and a leaf or two from the stem before planting and just ate those buts outright rather than waste them. And am now pleasantly buzzed even on a pinch of immature budlets
Got lung problems so I can't smoke much anyway; am glad I'll have some extra to try making glycerine drops, more cannabutter etc. Will save the best stuff for the smoker in the house.
hth