how far to keep light from seedlings?

[chockeyfan6]

So my 3 seedlings just sprouted out of 10, the question now is how far away should i keep my 600 watt mh bulb away from the 1/4 inch tall seedling!!?????

 

[RawCore]

as close as you can get them without burning the plant. if it feels uncomfortable on your hand it will burn your plants.

 

[1itsme]

far... like 4 ft. i would personaly use cfl till they get a little bigger. its cheaper and safer for the seedlings. 600 will work but you can burn them easy. hth

 

[RawCore]

are you using a ac hood or tube or just a reflector? how are your lights vented? I've been told 600w MH will work great and to get them as close as you can without burning them, because if you put the lights to far away it will cause them to stretch.

 

[dl290485]

It's not ideal to start a seedling out under 600w. It's a waste of power and you have to be careful not to put it too close.
When a plant is established, anything closer than 30cm is really risking over doing it. For a new plant, just like fertilizer you will want a quarter strength to start, then half then go to the closest the lamp can get when it's fully growing and ready

 

[dl290485]

Hmm that might of been a bit confusing.

Start at 90cm (4x 30cm because 30cm is maximum closeness)
go to 60cm when small still but not a little seedling
when it's established and growing then go to 30cm but even at that, your other conditions such as fans and ambient room temperature may push you over the temperature limit and you may have to back it away still.

 

[chockeyfan6]

Hmm that might of been a bit confusing.

Start at 90cm (4x 30cm because 30cm is maximum closeness)
go to 60cm when small still but not a little seedling
when it's established and growing then go to 30cm but even at that, your other conditions such as fans and ambient room temperature may push you over the temperature limit and you may have to back it away still.

ok well move it to 90cm cuz we had it at 60cm because we thought it would be fine since the humidity is at 70% and the temp was 85 F

 

[DONNYS]

So my 3 seedlings just sprouted out of 10, the question now is how far away should i keep my 600 watt mh bulb away from the 1/4 inch tall seedling!!?????

seedlings dont need much light

 

[DONNYS]

It's not ideal to start a seedling out under 600w. It's a waste of power and you have to be careful not to put it too close.
When a plant is established, anything closer than 30cm is really risking over doing it. For a new plant, just like fertilizer you will want a quarter strength to start, then half then go to the closest the lamp can get when it's fully growing and ready

good and sound advice