Anyone grow from seedlings under 315 CMH?

[pointer80]

Hello all, I just bought a 315 watt cmh for a 4x4 grow space and was wondering how many members have used this light from the seedling stage on thru veg. If so what is a safe distance to hang the light above seedlings. Thanks all.

 

[MassMedMan]

Not I. And I wouldn't recommend it bc it's serious overkill. The chances of bad things happening are much higher then good.

That being said if it's yer only option, I'd start at two feet. Those are great lights and very powerful. Tread carefully.

I run 630 CMH(s) on mature plants in veg/ early flower and im two to three feet apart. FWIW

Good luck

 

[Slowpuffer]

Hello all, I just bought a 315 watt cmh for a 4x4 grow space and was wondering how many members have used this light from the seedling stage on thru veg. If so what is a safe distance to hang the light above seedlings. Thanks all.

I recommend starting them under leds and then move them under the 315w 4200 bulb after about 2 weeks. if I had to start under the 315, then I'd put the light at about 2.5-3 feet away for 1st few days, then move down to two ft., and never get under two ft.. even in bloom, I personally never get under two ft from canopy, with a 630w fixture !!
Has anyone experienced early maturing under the cmh ?? I'm finding trichomes are going amber earlier, than under 600w hps. Can anyone confirm this, or tell me I'm hallucinating ??

 

[013]

I’ve ran a 315 but not on seedlings - it’s a good light but yes I’d keep it on the high side to be safe, if you see signs of stretch then you can make adjustments. Most have digital ballast so I’d crank that down to lowest setting for now. Then once it’s established you can begin tweaking wattage and distance - but err on the side of caution until you get a feel for it. Only takes a few minutes to cook one

 

[Bush Doctor 77]

I've done plenty under 400 and 1000 watt HID. Start at 36" for the first few days and slowly lower to about 18 inches. Different strains, and growing conditions(temp, RH) will impact your final height.

 

[ThaTinMan]

Woa! Does anyone own a LUX meter, they're cheap. Magic yellow brick road will show a much better path to the wiz. Pull the straw out of ya head...

4K. Using 315 cmh gives incredibly darker green, what everyone wishes for. Spectacular instant changes to the most woeful looking babies you have ever seen!

Get a clue, buy a 315cmh light with a LUX meter and you are set. So easy now it's kinda stupid.....

ThaTinMan

 

[ThaTinMan]

Woa! Does anyone own a LUX meter, they're cheap. Magic yellow brick road will show a much better path to the wiz. Pull the straw out of ya head...

4K. Using 315 cmh gives incredibly darker green, what everyone wishes for. Spectacular instant changes to the most woeful looking babies you have ever seen!

Get a clue, buy a 315cmh light with a LUX meter and you are set. So easy now it's kinda stupid.....

ThaTinMan

 

[pointer80]

Woa! Does anyone own a LUX meter, they're cheap. Magic yellow brick road will show a much better path to the wiz. Pull the straw out of ya head...

4K. Using 315 cmh gives incredibly darker green, what everyone wishes for. Spectacular instant changes to the most woeful looking babies you have ever seen!

Get a clue, buy a 315cmh light with a LUX meter and you are set. So easy now it's kinda stupid.....

ThaTinMan

So you are saying cmh are good deal for seedlings?

 

[ThaTinMan]

Outstandingly.

Now, if there is ANY problems, lift higher. 2k to 4k. Do not go lower than that with lights, in the beginning.

Switch to sodium in flower stage.

ThaTinMan...

 

[ThaTinMan]

Also, remember that PAR (or nm) is 3.05 times LOWER than LUX. Lux is 3k, then PAR is 983.

If you look at some grid spreads, for 315 cmh is as low as 580 PAR! AT CENTER! So there is a variant.

 

[ThaTinMan]

Here are some pics. First you will see at 4k. There are some interesting facts.
Each one is darker green. But the plants cannot take it at 5k (because they are taller.) Will yellow in minutes.

 

[ThaTinMan]

Here is at 3k for plants. And 2.5k for seedlings.

 

[ThaTinMan]

Seedlings just seem to love 4k. Plants are making a comeback, so there is that to consider also.

 

[ThaTinMan]

Other numbers..
At 78-80° humidity at 75% RH running 24/7. Keep domes on top until seed pops out.

 

[pointer80]

Here are some pics. First you will see at 4k. There are some interesting facts.
Each one is darker green. But the plants cannot take it at 5k (because they are taller.) Will yellow in minutes.

I didn’t know you could get a cmh bulb in 5k. Thanks