My very first grow was Hindu Kush, i'm a newbie and now only on my second grow (BLZ bud this time).
Three clones in an NFT 205 tank, left them alone, no trimming or topping. 3 weeks veg, and 5 flower (used Canna nutes throughout, and the grow guide i picked up from the shop), 400w HPS.
They grew well in veg, but in flower they stretched big time and each main cola grew really tall (about 6ft) and I ended up bending them over in the last two weeks cos they were right up in the light.
Was a lovely bit of weed though, tasted and smelt like red seal or squidgy black hash. Got 6 1/4 oz and a shit load of trim

.
Good luck with your grow.