Distance between 150w metal halide to plants in their first week?

[canabuder]

What is the optimal distance between 150w metal halide to the plants in the first week of growing?

Right now they are 2 days old and the distance in about 80cm, but I think that the leaves are too small and the plants are too tall.

I'll post a picture of them in a comment.

 

[canabuder]

Here are the images, they are about 1-2 days old.

 

[AgentPothead]

Whoever made the light should have recomendations. I've never used MH, but growweedeasy has generic recomendations.


Grow Light Closest ~ Sunlight Furthest
150W 8″ (20cm) 10″ (25cm) 12″ (30cm)
250W 10″ (25cm) 12″ (30cm) 14″ (35cm)
400W 12″ (30cm) 14″ (35cm) 19″ (48cm)
600W 14″ (35cm) 16″ (41cm) 25″ (64cm)
1000W 16″ (41cm) 22″ (55cm) 31″ (79cm)
I keep trying to edit that table and make it readable, but I just make it worse.

 

[canabuder]

Thank you. I've also found that, I just wasn't sure if it's not to close in the first week.

 

[Switcher56]

Thank you. I've also found that, I just wasn't sure if it's not to close in the first week.

Here is another recommended way to measure distance during the various phases of growth, using PAR values:

• seedlings ~ 60-90 umol
• clones ~ 100-200 umol
• veg ~ 300-425 umol
• flower ~ 700-1200 umol (requires CO2 above 1000 umol)

 

[GrowSwim420]

Hey I'm using a 600w my rn for veg and I keep mine about 18" away but my girls are a little over a month old. You def wanna do the back of the hand test. If it's too hot for you them babies will cook. With 150w I'm sure you want to START somewhere around 16-18" and maybe gradually lower to about 12" because 2 days old doesn't need much power anyway. Always remember to stick your hand under the light if it's not that warm drop it some more until you find the sweet spot

 

[GrowSwim420]

600w MH

 

[AgentPothead]

Always remember to stick your hand under the light if it's not that warm drop it some more until you find the sweet spot

You should do that with any light for sure! Some of these LED run warmer than people are expecting. If you can't keep your hand there for 30 seconds, it's too hot for your plants!

 

[troutman]

When plants stretch like that I place soil against their stem if the pot allows.
Roots will form along the stem improving the health of the plant in time.

As for your light, just work your way down a few inches each day from where it is now.

Heat on the back of your hand at plant height is a good test as AgentPothead mentioned above.

Go slow and all will be fine.

 

[Ace Rothstein]

To address the initial length of the stem I plant in a 2/3rds full plastic cup, when they get too tall , just add the final 1/3 of soil to support the plant. Have a fan on moving the plants gently.