Starting with 400 MH

Ive got about 40 plants to start off with a 400 watt MH. First of all, if this to much heat and lumens to start them? If it isnt how far should the light be from the top of the soil? Quick help because im startin in a few hours. Thanks

you can't have excess lumens, but for sure you can have excess heat
when you say "start off" are you referring to clones or seedlings?
probably the safest thing to start with is CFL's until the plants have expanded root growth
a MH lamp is OK if it is 3-4 feet away from the top of the new plants with lots of air circulation and a way to vent the heat

They are seedlings....although i have one cfl which is a 150 watt with a hood. But theres no way that it can cover all 40 plants, because the cfl are meant to be onle and inch away from the plants and im not sure it could cover all 40? Is it going to be a waste of my time starting them with a 400 mh?

jeffchr said:

you can't have excess lumens, but for sure you can have excess heat
when you say "start off" are you referring to clones or seedlings?
probably the safest thing to start with is CFL's until the plants have expanded root growth
a MH lamp is OK if it is 3-4 feet away from the top of the new plants with lots of air circulation and a way to vent the heat

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I'm reffering to seeds....I have one 150 watt cfl, although its not gunna cut it for all 40 plants. Will the 400 mh screw them up for later reasons? has anyone ever tried this?

As stated above, start the light off at about 3 feet away. Gradually work it closer and you can't go wrong. They will grow much quicker and a lot more vegetation under the MH.

40 plants?? and how many grows? lol with a 400 your better off pulling qwops off 2 plants. your 40 plants are gonna all be popcorn... a waste imo.

I just received my 400W MH/HPS a couple weeks ago and I started the seedlings under MH, about 3-4 feet away as said already. They are all very healthy looking plants now. Nothing wrong with using a 400W MH for the seedlings

Dr.RR said:

I just received my 400W MH/HPS a couple weeks ago and I started the seedlings under MH, about 3-4 feet away as said already. They are all very healthy looking plants now. Nothing wrong with using a 400W MH for the seedlings

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excellent...very good to know! Although i asked this in another post; is it alright to throw the germinated seeds in the soil and instantly have the light on them, or should i put them in the dirt and let them sit in the dark for 24 hours?

ive had my 400 a foot off new seedlings and cuttings and did no damage but ive got good airflow/air cooled hoods. mh would be way better than cfl

alright thanks alot....ive got plants of fans, would it work to put a fan on high so it directed winds right across the top of the soil? Whats a good idea?

hazemaster said:

alright thanks alot....ive got plants of fans, would it work to put a fan on high so it directed winds right across the top of the soil? Whats a good idea?

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This will blow your seedlings away lol. Keep some air circulating, but no direct air towards the seedlings. I have my fan in the back of my closet and the plants in front of the fan. The fan is about 1-2 feet higher than the tops of the plants and blows air across my 400W HPS (~1 foot beneath the bulb), works pretty good. Blows the hot air out the door.

My fan is also on low but moves a LOT of air. Just check it every once in a while, because you don't want the fan to be blowing right at the plants so the tops are blowing off.