Bmeat, Quit giving advanced grow advice. Your plants look like shit, and your mouth is full of shit. My advice to the OP, dont listen to Bmeat.
LMFAO.....
If everything is healthy, your plants could streach after they have been put into 12/12 after veggin' for 4-6 weeks... Strain dependant...
Sativa's will streach moore... than Indica's...
If I put a very healthy 16" plant [hybred] at 4-8 weeks, into 12/12 from 18/6... it will usually streach to 20-22", generally I figure 33% growth after light switch.
Strain, and light/soil/hydro dependant....
I grow a little different than most, [limited space], I like two foot plants, many of them, in my grow space.... I also like fresh pot, and I am hands on...
So, weekly/every other week, I clone at least 4-8 plants... clones from clones, or from mother.... clones I am cloning from, are 5-8 weeks old, and cutting has at least two equal sets of nodes...
Then, I take four plants from 18/6 that are 12-18" tall, and put them into Bud room for 8 weeks of 12/12
Every week, I take out four small plants, dry, cure....
Then I smoke w/gf four plants weekly...
Next week I start over...
Enjoying every minute....