400w MH distance

[cwesto]

My plants are 3 days out of the ground, still lil guys. My Q is how far away should my 400w MH be away from my babies, right now i am about 4 1/2' and how old should the plants be when i move the light in reall close??

cwesto Reviewed by cwesto on 10-30-2007. 400w MH distance My plants are 3 days out of the ground, still lil guys. My Q is how far away should my 400w MH be away from my babies, right now i am about 4 1/2' and how old should the plants be when i move the light in reall close?? Rating: 5

[the image reaper]

keep them FAR away for awhile, lol ... I just found out the hard way with my 400-watt HPS ... placed seedlings about 2 feet away, bleached them white as a sheet ... had me totally clueless (I had recently gotten the big lamp, didnt know they could do that) ... they recoverd, but I lost couple weeks' growth due to it, seemed to handle it better after the first couple weeks ... :jointsmile:

[cwesto]

Reaper here r some pics of my babies, the only reason i ask for a distance in the begining is b/c the yseemed like they are stretching, heres some pics please give me ur opinion if i should move em closer..... they are at about 4 1/2' right now

[PharmaCan]

My plants are 3 days out of the ground, still lil guys. My Q is how far away should my 400w MH be away from my babies, right now i am about 4 1/2' and how old should the plants be when i move the light in reall close??

There are a lot of variables at play here; from strains to individual plants. Watch your plants and, when they begin to stretch, move the light a little closer. Once the plants start to grow, they'll be strong and healthy enough that you can experiment with the lighting to find what is ideal. But the seedlings are sensitive, so you need to be careful with them, like Reaper said.

PC :smokin:

[Dutch Pimp]

I started out my seedings for one week under 4ft floros. Then I switched to 400CMH bulb, 15 inches from the plants. Going on week #3. 11 inches from plants, plants about 10 inches tall now...sweet. Temps about 77-85 degrees at top of plants.

[cwesto]

yea i had my CFL's on em for like 2 days, and i was told to put my CMH 400w on them, so i did. Ive never grown from seeds so im not experienced on identifying strectch at this stage in their life. Anyone with experience please look at the pics and let me kno what u think i should do.

[SMOKEnCHOKE]

They do seem to be stretching. I would just gradually move it closer to them, but don't burn them it's easy to do. How high is the light now?

[Twentyinches]

Reaper here r some pics of my babies, the only reason i ask for a distance in the begining is b/c the yseemed like they are stretching, heres some pics please give me ur opinion if i should move em closer..... they are at about 4 1/2' right now

bringing an old post from the dead lol, hey cwesto is that all the light that 400MH puts off?

[Roughrider]

Well, just my opinion...but I'd consider keeping the plants under CFLs for at least 10 days; two weeks would be better. The plants will be halfway through the seedling stage by then, and you should have enough leaf area to really take advanage of the extra light of a MH/HPS.

But, yeah, keep them far, fara away at first. CFL to MH is a shock; you'll crisp up your leaves if the lights too close. (Been there, done that.) You'll either lose the plant or lose a 2-3 weeks of growth while the plant recovers. Still, I haven't seen anything to indicate that plants grow faster under a MH in the first 10-14 days. After that, yeah.