Just wanted to say hello. I'm a newbie on here but have been trolling for a year now. I've learned a ton from you guys thank you. I'm a pretty educated grower who definitely does my research. My current grow is using 6 LECs CMH Phillips 315 vertical bulb with 3100K. These are Sun Systems units. My grow area is a bedroom so it's large enough but actual grow area is about a 6x10. Have a dual hose AC at 14k btus. I'm using soil with Nectar of Gods nutes line. I've had great success with prior grows with this nute lineup so keeping it again. Strain is White Queen from Amsterdam. It's a hybrid that grows short. I started from a seed to grow the momma and now my clones are currently under T5 HO until big enough to move under CMH. I'll attach pics soon of momma and babies. Momma is currently under 2 lights both LED 3070's each with 6 LEDs running 50watt per led. She's absolutely loving it and is on day 22 of flower. Ok guys sorry for long message just wanted you to know what I'm working with.
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Philips 315w CDM Elite (CMH)
- Thread starter rives
- Start date
plumbum
Member
Hi you guys, very interesting and informative thread here, thank you. I am looking for a practical advice. I am setting up a veg area and considering using Sunlight Supply 315 3100K all in one fixture with vertical bulb. What do you all think, is it a good choice for veg? Somebody in hydro store told me that I would need to keep it as high as 6' from canopy since the light is very bright. Seems kinda extreme to me. Maybe somebody who has experience with these lights could comment. My biggest question what is proper layout for these lights for veg. What area do they cover? How many watts per square foot should i shoot for? And what is reasonable hight above the canopy to keep everything happy. I hear numbers from 2.5x2.5' to 4'x4'? quite a difference.. I used to veg from 600 MH covering 3x3 to 1000 MH covering 4x4 raised quite high. By switching to LEC I am trying to save on electricity and hopefully have a better plant structure.
thank you very much!
here is a picture of plants that were veged under MH
thank you very much!
here is a picture of plants that were veged under MH
oti$
Active member
6' above the canopy is too high. 2'-2.5' is about right. I had a 315 lighting a veg area about 5x5 and 5he plants on the edges were stretching a little more than I would have liked. I have moved it to a 4x4 space and it seems to be about right. For flowering you might want a slightly tighter area. My experience is limited to a couple veg cycles and 1.5 bloom cycles with cmh, fwiw...
If you plan on using the fixture just for vegging, you might want to consider the 942 lamp (4200k). Theoretically, at least, it provides a better veg spectrum and some people like it better for flowering. I find that the coverage works best up to 3x3 for flowering, at somewhere around 35-50 watts/sq.ft.. The coverage should be wider for vegging, but I veg under LEDs and don't have any direct experience with it. You might need that much headroom for a fresh start, but not for established plants. I've run anywhere from about 2' of clearance to brushing the glass with no issues. If you are running an open fixture, you would obviously need to stay a bit further away.
plumbum
Member
thank you rives, your advice is very appreciated. i am going to go with open fixture and will look into using 4200k bulb. i was thinking that since LEC light has good spectrum to start with, the 3100k should be a bit better by providing more light. freshly rooted clones will go straight under that light. i guess i should be careful to not stress them out at first by raising light higher.
Plumbum-
Rives is right on the 4200k better for veg plus more UV light which has been proven to be beneficial. But I'd recommend 3100k for flower for sure! As far as coverage I think 4x4 in veg is pushing it and a max of 3x3 in flower. I'm personally running same fixtures about 33" from center to center so about 2.5'x2.5' spread. I like a little over spread with light. Whoever told you 6' high is an idiot or just not educated and experienced. You'll get way better penetration and par moving it closer. I agree with rives with 2' or closer.
Rives is right on the 4200k better for veg plus more UV light which has been proven to be beneficial. But I'd recommend 3100k for flower for sure! As far as coverage I think 4x4 in veg is pushing it and a max of 3x3 in flower. I'm personally running same fixtures about 33" from center to center so about 2.5'x2.5' spread. I like a little over spread with light. Whoever told you 6' high is an idiot or just not educated and experienced. You'll get way better penetration and par moving it closer. I agree with rives with 2' or closer.
Depends on how much degradation you're comfortable with. Phillips says 93% efficacy @ 8000hrs for the 942, and 90% for the 930. That's over 16 months at 18/6. Personally, I've dated all my bulbs with a marker, and will replace them every 18 months. FWIW I'm about 50/50 between 12/12 and 18/6. I'd rather maintain a higher efficacy, and replace to bulbs sooner. Hope that helps
For anyone still interested in this, I checked my individual ballast (Philips in an aluminum case) this morning before lights out. It had been on for 11-1/2 hours and the warmest reading on the housing was 92°, ambient was 72°.
It won't make any difference because watts is the measure of heat.
There have been numerous reports about the 120v ballasts running substantially warmer than the 240v versions. The lamp wattage remains constant, but apparently the ballast losses get worse.
