Yep, I only use that 400W HPS throughout the whole grow
Those plants I grow are really fast starters, my previous grow they were even faster, this time they were a little bit slower, due to the skunk father, but they seem to be compensating in bud size
It is a WEED, and if the conditions are right, it will grow like crazy, I see many people here that have 4 weeks old plants that look smaller than my at day 5, but thats all due to overwatering/ high or low temps/ poor lightning - those are the most frequent mistakes when starting
You can also try some LST - you don't really need tall plants, and with indica you have very good conditions to make really bushy plants, and the good thing about bushy plants is that all colas are closer to the light, with a tall plant you get only one main cola that is close to the light, and the rest of the side branches are lower, and light decays in quadratic rate with distance - since light will be the most determining factor for yield you are far better with bushes instead of tall plants, the plants will be able to absorb more light and make bigger buds
search the forum for LST (low stress training) if you don't know what that is