what could be the problem??

i have 50 plants 2 weeks into veg and they are all the same strain ssh. 10 of them are real bushy and about 12in tall. 25 of them are not bushy at all and are 14in tall. 15 of them are 12in tall and just look like a tall stem with some leaves on it. all plants treated the same and have been moved around the room. they all looked the same when transplanted into 3g pots with the same soil mix.

i am wondering why there would be so much inconsistancy? they are in a big room with 4 1000w hps, fans, co2, temp 75, hum 35-40.

3 phenos is reasonable.

Like UserFriendly says: "Phenotypes". Basically slightly different versions. It gets insanely complicated. If you are interested, scroll down to the Genetics or Breeding sections and start reading.

Marijuana Botany