Why is it stretching???

(-)_(-)

Well-Known Member
I have a 400w hps light about 2 1/2 to 3 feet away from the sprouts but the stems are pretty long - like almost 2 inches and It's only been about 2 days since they came outa the ground. They look like they are getting plenty of light but they keep growing taller instead of fatter. What the hell????????
 

(-)_(-)

Well-Known Member
ok - it started out about 4 feet away and i lowered it 4 inches the first day but 2day i noted them getting pretty tall so i lowered the light alomst a foot they are in the dark phase rite now so i gess i'll lower the light even more in the morning.
 

videoman40

Well-Known Member
yes, move the light closer, daily. What iis the temp difference from night to day? A difference of more that 12 degrees will also induce stretching.
Assuming you have exhaust, and a oscilating fan, get that light at about 15" for now.
Of course when you do your next transplant, you can easily bury a portion of the stem in the soil.
Peace
 

(-)_(-)

Well-Known Member
i dont rly have a way of telling the temp but i'm pretty sure the temp change is not that drastic but thanks 4 the help - i'll lower the light to about 15" 2morrow morning.
 

mogie

Well-Known Member
Recommended typical OLH distances:

Flourescents: proximimty
400w HPS: 1 foot
600w HPS: 1.5 foot
1000w HPS: 2 foot
 

(-)_(-)

Well-Known Member
the plants are all still stretching - should i just fill in some more soil around thier bases???
 

babygro

Well-Known Member
the plants are all still stretching - should i just fill in some more soil around thier bases???
HPS lights used for vegetative growth will cause your plants to stretch - there's nothing you can do about it except switch to a MH or 6,400k CFL.

Your plants will stretch regardless of how far the light is away - and a 400w HPS 12 inches away from seedlings breaking the soil surface 2 days ago IS TOO CLOSE REGARDLESS OF WHAT PEOPLE ON HERE HAVE MISTAKENLY TOLD YOU! That light should be at least 3-4 feet away from those plants at this stage in their growth - having it any closer will not stop the stretching.

Seedlings and rooting clones only require about 500 lumens per sq foot - that HPS is putting out 50,000 lumens at 1 foot distance! There's very little photosynthesis going on at this stage in their growth - most of the growth is happening below the soil surface - so why do you need so many lumens on the plants?

Your best bet is to get an oscillating fan on those stems as soon as practical to start thickening them up and depending on how bad the stretching is - when you repot them bury as much of the stem length under the soil as possible - it'll just form part of the root system.

HPS is not an ideal light to veg under for this very reason - I've forgotten now how many times I've said it but still people take no notice.
 

BluBerry

Well-Known Member
If you have enough room to fill soil around them then I would do so I did it to mine. But you need to go to walmart and get a $6 thermometer that tells the temp. & humidity. It is really helpful. And once you get one if the temp is below 75 then move the light closer about half a foot.
 
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