315 Migro CMH hang height?

For seedlings I would keep it pretty high at first. Probably right from the top of the tent. Once your babies get a bit taller and have some roots going lower it down to 2’ or so.

I just setup a room using 315’s and have found 2’ to be good for my purposes.
 
Your seedlings will stretch when the lamp is that high, i would suggest cfl's for the first couple of weeks. Why waste that much energy on seedlings is also something to think about.
 
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As nurrgle said is good advice imo - if they start to stretch lower the light a little at a time if the get really leggy you can always bury the stems a little deeper when you go up a pot size ☮️
 
thanks for the advice guys. these will be auto flowers however so im not trying to replant at all. think im gonna run 3 or 4 cfls for the first week or 2 then turn on the 315 a few feet away from the plants
 
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lee1000 said:
Your seedlings will stretch when the lamp is that high, i would suggest cfl's for the first couple of weeks. Why waste that much energy on seedlings is also something to think about.
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They will not stretch when it is hung that high, I'm using a 315 in a 3x3x6 and its hung at the top approx 4' away, inter nodal spacing on multiple strains is 1 cm on average and the plants are staying quite compact sitting on the ground of the tent.

In a 2x4x6 tent your gonna have the same issue as me, I hope you got a huge ass fan for extraction as that light is going to heat up that small space quickly.
 
nc208 said:
They will not stretch when it is hung that high, I'm using a 315 in a 3x3x6 and its hung at the top approx 4' away, inter nodal spacing on multiple strains is 1 cm on average and the plants are staying quite compact sitting on the ground of the tent.

In a 2x4x6 tent your gonna have the same issue as me, I hope you got a huge ass fan for extraction as that light is going to heat up that small space quickly.
Click to expand...
Yeah cmh has plenty of blue so you won't see much stretch... I agree. 5 feet away for seedlings i would say
 
awesome that's great to hear. and getting a 4 inch carbon filter/fan setup, im hoping that'll cool it along with 2 small fans
 
You should be fine on heat. I have 15 in a small basement room with no AC

Smell on the other hand might overwhelm our filter
 
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