lights to powerful

Nike617

Well-Known Member
hey everyone, im using a 600 watt mh for vegg and a 600 watt hps for flowering. I dont have cfls for when my girls have just sprouted and when they are only a few inches tall. So im just wondering if I keep my 600 watt mh about 5 feet above my girls will that be ok so I don't fry them. and then move the lights down to normal hight when they reach about 5-6 inches? thanks in advnace
 

Nike617

Well-Known Member
ok sounds good. My plan is to start of at about 5 feet then bring it down a few inches a say then when my girls reach about 6 inches or so ill put them at reg hights
 

GrizzlyAdams

Well-Known Member
I ran into this problem once. If you're going to use that chart i'd say its best to almost be in the "too little light" category. Using an HID thats that powerful on seedlings won't kill them, but it can retard growth and limit potential. If your ballast has a dimmer I'd recommend 50% power and 3 feet up or 75% and 5 feet up. Soon as they grow some solid big leaves and can take more intense light step it up and move it closer.
 

Clevelandblazn5

Active Member
I also have a 600 watt mh in a 7x2 closet with 8 seedlings under, my light is 5 1/2 feet above hanging from the shelf as soon as my seedlings broke threw the soil I turned it on and set my tray on the ground they have been growing amazingly the past day in a half they are about 3 inches now and I have had no problems except for 2 of them are starting to lean over but they all have leafs on them and are growing rapidly I have a centrafungal fan with exhaust cooling the room the light emmitts a lot of heat so have a ventalation plan before you over heat
 

Nike617

Well-Known Member
I know but I just want to use my mh as I would if it was vegg well im not using the light until the plant sproutes above the soil. and grizzly adams I dont have a dimmer so I think im going to do about 5 feet above them until they reach about 5 inches or so. What do you guys think. should I move light to reg hight when my girls reach 5-6 inches or should I wait till its taller or is that a good hight?
 

thesmokering

Well-Known Member
You got to have light on for sprouting or else it will get confused and not grow in the right direction. As for when to move the lamp, the best indicator is just putting your hand out and feeling the heat on it, is it uncomfortable? If it is then the light is too close or the ventilation is not good enough. My best plant has a cold air intake brought right up to the cola so that its temps are always good.
 

AirAnt

Well-Known Member
You got to have light on for sprouting or else it will get confused and not grow in the right direction.
Wrong, sir. Marijuana is a gravitropic plant and so orients itself according to gravity, not light source. Lights are not necessary for sprouting and often even do harm.
 

thesmokering

Well-Known Member
Wrong, sir. Marijuana is a gravitropic plant and so orients itself according to gravity, not light source. Lights are not necessary for sprouting and often even do harm.
lol, lights dont do harm, how long is that thing gonna last without light, the point is pointless because time between sprout and light needed is so short anyways. Plants do grow toward light though, so they would start growing towards the nearest light leak, probably not a big deal either though.
 

AirAnt

Well-Known Member
lol, lights dont do harm, how long is that thing gonna last without light, the point is pointless because time between sprout and light needed is so short anyways. Plants do grow toward light though, so they would start growing towards the nearest light leak, probably not a big deal either though.
I've read threads here about people that planted seeds, turned on the lights and fans, and then their soil dried out, killing the seedlings. They will orient themselves torwards the light in order to capture more of it, but that doesn't mean that without light the plant would mistakenly grow leaves below ground with roots up top. Now that'd be something to see.
As far as how long they will last without light...before I got my current grow going in earnest I prematurely sprouted some seeds in a tupperware container in some paper towel. I think I left them in there for about two weeks after they had sprouted, to the point where they were rooting into the paper towel and pressing against the lid of the container. No light. Moisture is more important to a sprout than light.
 

Nike617

Well-Known Member
I don't plan on giving it light until it sproutes above the soil and once that happens the light will be about 5 feet above my girls.
 
Top