-
As of today ICMag has his own Discord server. In this Discord server you can chat, talk with eachother, listen to music, share stories and pictures...and much more. Join now and let's grow together! Join ICMag Discord here! More details in this thread here: here.
Philips 315w CDM Elite (CMH)
- Thread starter rives
- Start date
White Beard
Active member
Hey, thanks! 60w/sqft too much? Would that be modulated by reflector flush-mounted to a top panel, in terms of heat?
Not sold on the idea of 36/36/630, just trying to imagine the next level up, 48/48/630 PPW drops to 40...what’s the lightprint for a de 630?
Not sold on the idea of 36/36/630, just trying to imagine the next level up, 48/48/630 PPW drops to 40...what’s the lightprint for a de 630?
It's not so much a question 60w/sq ft being too much as it is 36x36 being too little. W/sq ft is a bit dated but is a decent general indicator. This method assumes that all watts will equal one another for even distribution and we know this to be false. Center point may yield 725 PPFD while edges may see 350PPFD.
In regards to securing a reflector to the highest point, this is not an uncommon practice in tent and limited height applications. Adding distance between the canopy can of course reduce heat and intensity, but may be insufficient for cooling alone depending on ambient temps, whether cool air intake is being implemented, etc. In limited space applications, I have personally found ACDE hoods to be useful.
Any closer than 2' to canopy can risk light and heat burn, particularly in an environment that is not controlled (ac, rh, c02 etc) and will offer diminishing returns.
As far as footprint, most people run 4x4' - 4.5'x4.5'. I have spoken to people who did 5x5 but was a little surprised by this feedback.
I would love to get footprint feedback from growers running vertical CMH.
Hope this helps.
In regards to securing a reflector to the highest point, this is not an uncommon practice in tent and limited height applications. Adding distance between the canopy can of course reduce heat and intensity, but may be insufficient for cooling alone depending on ambient temps, whether cool air intake is being implemented, etc. In limited space applications, I have personally found ACDE hoods to be useful.
Any closer than 2' to canopy can risk light and heat burn, particularly in an environment that is not controlled (ac, rh, c02 etc) and will offer diminishing returns.
As far as footprint, most people run 4x4' - 4.5'x4.5'. I have spoken to people who did 5x5 but was a little surprised by this feedback.
I would love to get footprint feedback from growers running vertical CMH.
Hope this helps.
Last edited:
I've never gotten a pound, and average from 13-14 ozs. It might be possible to get a pound, but it would take more attention to things than I want to do. My setup is geared toward low maintenance - I am usually gone 10-12 days a month.
I've had better luck with 3-5 plants than with 1 or 2. It always seems like there is one plant that doesn't thrive quite like the others, and it has a much smaller impact with greater numbers. I have had good luck with lower numbers and a scrog, but it is a hell of a lot more work and access becomes difficult.
A 630 in a 36x36 would be a bunch!
Other than keeping an eye on Hammerhead's experimentation, I haven't really paid much attention to recent developments. I tend to stick with what works for me and ignore things until those needs change. I'm glad to see that there is enough interest in this technology to have driven offerings from a variety of vendors, but think that it would be pretty difficult for anyone to beat Philips' gear. I used it for 30+ years in an industrial environment and the the demands of that are so much more rigorous than what growers find acceptable that the two markets aren't even comparable.
In my experience, it hasn't been an issue with the strains that I run. I use enclosed & ventilated hoods, and try to finish out at about 18". There have been a couple of times when I miscalculated on the flip and had the buds brushing the glass without any ill effects other than screwing up the light distribution.
No, that is with 315's, but it includes two 315's in a 4x4 (separate hoods) with the two hood's ventilation air run in series. Not sure how comparable that would be...
The hoods and the glass are barely warm to the touch, so the only potential issue would be light burn.
I'm using 315 in what is basically a 2.5' x 2.5' per lamp foot print. Smaller than most have decided to go. The only complication with a reduction in square footage is an increase in cooling needs.
There is not right or wrong per say, until you start calculating production output vs input costs. Otherwise, it's just a balancing act of your parameters between proper environmental conditions. There is a give and take for every scenario, you just have to understand those parameters and operate in a manner that keeps you in the sweet spot.
Many growers think THEY grow the plant. It's a philosophically backwards approach. The plant grows itself as a result of environmental stimuli. As growers, all we can really do, is learn how to control the environment to trigger a desirable genetic response.
dank.Frank
There is not right or wrong per say, until you start calculating production output vs input costs. Otherwise, it's just a balancing act of your parameters between proper environmental conditions. There is a give and take for every scenario, you just have to understand those parameters and operate in a manner that keeps you in the sweet spot.
Many growers think THEY grow the plant. It's a philosophically backwards approach. The plant grows itself as a result of environmental stimuli. As growers, all we can really do, is learn how to control the environment to trigger a desirable genetic response.
dank.Frank
Snook
Still Learning
Faster finishing times?
Faster finishing times?
So let me ask.. 1st, while I've read a great deal of this thread, I have not read every post...and I do remember the subject of finishing time differences but not the answer, definitively. I had 2 GDP seeds gifted to me that were gifted to them, so who knows for sure what they are.. but going under the premise that they were genuine of some sort, popped them, one did one did not make it.. it was a girl (was it a fem seed? WTF knows) it is at Day 35 of bloom and decided to take a branch for closer inspection... 10%red trichs. Checked other leaves and the buds.. 10%. 3 weeks before harvest date I was aiming at. Could the CMHs produce that much quicker maturation? and I will check the other 3 plants later today but just finished a couple popcorn buds taken at day30 form another plant and it works very nicely.. didnt check the trichs i was defoliating..
Faster finishing times?
So let me ask.. 1st, while I've read a great deal of this thread, I have not read every post...and I do remember the subject of finishing time differences but not the answer, definitively. I had 2 GDP seeds gifted to me that were gifted to them, so who knows for sure what they are.. but going under the premise that they were genuine of some sort, popped them, one did one did not make it.. it was a girl (was it a fem seed? WTF knows) it is at Day 35 of bloom and decided to take a branch for closer inspection... 10%red trichs. Checked other leaves and the buds.. 10%. 3 weeks before harvest date I was aiming at. Could the CMHs produce that much quicker maturation? and I will check the other 3 plants later today but just finished a couple popcorn buds taken at day30 form another plant and it works very nicely.. didnt check the trichs i was defoliating..
My lights have no glass. I keep them all 24" above my plants. The worst Ive seen is crispy pistils.
I have seen a week or 2 faster finishing times but never more than that. I still take all my plants between 65-75 days.
I have seen a week or 2 faster finishing times but never more than that. I still take all my plants between 65-75 days.
Snook
Still Learning
It depends how much heat u need in the space u have. CFL don't put out much heat.
HorseBadoritiz
Active member
I have 6' floor to ceiling, so everything's low, lol! I'm running 5x 315's in different spaces w/ no glass, anywhere from 10-18" above the canopy... no ill effects. But closer than 10" can make things a bit crispy, unless a mover is involved. I can keep that one 2" from the hood.
I do have a lot of ventilation!
I do have a lot of ventilation!
White Beard
Active member
Curious as to whether you gents have been noticing shorter veg times too. Plants getting tall enough to flip on time, or early (or late)? Or not?
That could amount to a shorter season, which would also save a bucket load on watts, if it proves to be a thing for each phase.
In veg I leave them be until there large enough. There is no such thing as a quicker veg time. U can flower a plant at anytime.
I veg under LEDs (the VolksLED in my sig line), and have never tried the 315s for that purpose. With the reduced light requirements in veg, you should be able to dim the 315 down significantly.
White Beard
Active member
You anticipate me: I wasn’t really thinking about that aspect, but it’s true, my highly-trained brain weasels are captivated by the idea of running dimmed during veg, then opening up the gate for flowering...and maybe dimming back down as the end of flowering approaches (nothing cute or fuzzy about it) to encourage the ripening to complete. Because why not. I’m that guy.
So what is the ideal tent/box size for a 630 setup, the lightprint? And how does that change from dual-bulb to double-ended?
And if you please, what would you say is the ideal lightprint of a 2x 315 SE setup? I’m perfectly willing to build-to-order. Obviously I’m trying to decide between a single and a double CMH, or three singles. I’m working off your observation that 30” square was perfect for a single 315, and took a big step from “how big a tent do I need” to “I could have three 30” sq. units, each with a light and one plant, couldn’t I”.
That’s kind of a fixed point in my thinking now, but I don’t have a sense for if/whether/how the dual units might fit into that.
Or you could tell me how to figure it out for myself, that’d be fine.
Don’t even have one yet and I love the idea of what I can try with my new light....
I tell ya, deciding to actually DO this has been amazing...I never studied this hard in school - or enjoyed it this much.
So what is the ideal tent/box size for a 630 setup, the lightprint? And how does that change from dual-bulb to double-ended?
And if you please, what would you say is the ideal lightprint of a 2x 315 SE setup? I’m perfectly willing to build-to-order. Obviously I’m trying to decide between a single and a double CMH, or three singles. I’m working off your observation that 30” square was perfect for a single 315, and took a big step from “how big a tent do I need” to “I could have three 30” sq. units, each with a light and one plant, couldn’t I”.
That’s kind of a fixed point in my thinking now, but I don’t have a sense for if/whether/how the dual units might fit into that.
Or you could tell me how to figure it out for myself, that’d be fine.
Don’t even have one yet and I love the idea of what I can try with my new light....
I tell ya, deciding to actually DO this has been amazing...I never studied this hard in school - or enjoyed it this much.
I can't help you with the 630, I've never run one other than (2) 315s in a 4x4. One thing that has sparked a concern for me about the dual lamp fixtures is the potential for hot spots and uneven light distribution. I have a fair understanding of the R&D that has gone into trying to attain homogeneous light distribution with conventional fixtures, and don't believe that anywhere near that effort has been replicated with the dual lamp variety. I've had runs done on specialized lighting software for factory floors to try and insure even lighting levels, and it gets damn tricky even without having two light sources in a given fixture. It's entirely possible that they work better than I would think, though.
For (2) 315s, I would go with 30x60 or a close approximation. When I was running the 4x4, I had too much light in one axis and not enough in the other. Other hoods would certainly give somewhat different results, but...
I think that your enjoyment has just started. If you've spent any time working under HPS, LEDs, or damn near any other lighting family, you will be astounded at the difference in being able to troubleshoot plant issues and simply enjoying the spectrum that humans have thrived under since time immemorial.
White Beard
Active member
Good to know, thanks for the input!
Once again, thanks: that checks out with my own evaluation.“Rives” said:
I agree completely on the natural spectrum...my eyes give me enough shit without wandering around in a leafy disco.“Rives” said:
You’ve settled me: going with the 315 into 30x30, multiplying that as I go. Another round of appreciation, sir.
Home-Grown
Active member
`
Last edited:
