stem length?

Hey people! Just started my first grow (vanilla kush from seed) and I've been doing as much research as possible. I've read about long stems being caused by not having the light close enough, however as this is my first time growing I'm not sure how long is long?? Roughly how far from my growing medium should my first set of leaves be? I'm growing in coco and using a 600w hps (I know not ideal but at the minute it's all I have) and I'm worried about frying them by putting them too close.
So....
1. How long should stem be up to 1st leaves roughly?
2. Any suggestions on how close I can go using a 600 hps?
Cheers in advance!
Hmmf

pic would help

If your hand is hot the girls are hot.

Also, fresh seeds do not need a 600 watt. T-5 Fluro is plenty until they are a little more established.

And yes, pics would help. Also, what strain - Indica/ or Sativa, Hybrid? Are the seedlings falling over? That is a good indication, lol.

u can use ur 600W but its a waste of energy for seedlings. a small floro would be better. to answer ur question I would keep ur light about two feet away from those little plants. with that kind of par they should be pretty sturdy. and as the other post explained if ur hand between the light and ur plant is hot then its too close.

Cheers for the quick responses, Il try put some pics up tomorrow.
I have looked into the t5's but won't be able to get my hands on one for at least 2 weeks "/. Im growing vanilla kush (indica dominant hybrid) one of three is still relatively short compared to the other two, so I'm not 100% if it is the light or just the girls doing what they do! Could it just be different pheno's? Can they start showing differences this early on? (Couple of weeks tops). Cheers again guys
Hmmf

This should help yah man w/ your light distance.



Good Luck on Your Grow.