Any Help?? Switching from 18/6 (veg stage) to 12/12 (flowering stage), 1st time growr

Just last week i trasnplanted clones into large rockwool cubes and started 18/6 veg cycle. How long (roughly) should i stay on 18/6 until i go to 12/12. I was told from an experienced grower that i shouldnt stay in the 18/6 too long, maybe only a total of two-2 and a half weeks then straight into 12/12? ANy input? BTW, my advice giver does straight 24on 7 days a week until he switches directly to 12/12. He gets great results. Hes telling me that If i stay in 18/6 to long the plants will get tall and lengthy and not bushy like hes use to. Im a first timer so any advice helps. Thanks

IMO - For minimal stress, start the first 3 days at 18/6...then gradually adjust the hours (each day)...19/5, then the next day would be 20/4 and so on...until you hit 24hrs. I personally would wait till she's at least 1' tall then go into the flowering stage...any strain is known to double and triple in heighth during the transition to full bloom...2-3 weeks of vegging is fine too...all depends how much you want back in return.

The distance of the nodes (lanky stuff) will also depend on the health condition and type of light you use. I normally get short nodes using about 600w (400w MH + 250w MH). Lil late but hows your plant doing?