315 CMH

Xochipilli

Xochipilli

New member
question: what seems to be the optimum distance for 315 CMH? I am flowering under 3100k bulbs now. I had originally spaced the lamp about 2 feet from the canopy - the CMH seems to have really diminished the amount of stretch that I normally count on. Strains that normal double or more in size have barely stretched at all. I am wondering if I am too close with these bulbs. I have read one distance recommended is 36 inches? Curious what experiences folks here have had with these bulbs...

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I found that using the CMH i need to keep my tops right at 3' from the fixture...that distance seems to be the sweet spot for massive amount of flowers with minimum stretch as you've experienced...I've not tried them in flower yet as I'm happy with the HPS results...
 
I'm flowering with both HPS and 3100k CMH. At this point, a few weeks in, the plants under HPS look slightly more advanced in maturity but not by much. The biggest thing I'm seeing is reduced stretch with the CMH, and this effect appears significant in some strains....

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hey definitely take some getting used to. I dont kill it every run yet. Some have been downright embarrassing but others have been over the top. 5 zips was my worst run and 17 my best.
Yes stretch is reduced and in many cases a lot as you have noticed. They also go into flowing much quicker and finish up faster. On average by about 4-7 days or so.
The solution of course is more veg time. In veg the plants will grow right into the light without any damage but 36" is what they recommend. In flower I have gone 18-36.. Not sure I can tell much a difference. . However I have gone 100 organic so as soon as I get everything dialed in with the organics I will play with heights some more and do a side by side.
One thing I have noticed is in a tent I get better yields. I just redid my main room so I put mylar on all the walls and will see if that helps.
 
hey definitely take some getting used to. I dont kill it every run yet. Some have been downright embarrassing but others have been over the top. 5 zips was my worst run and 17 my best.
Yes stretch is reduced and in many cases a lot as you have noticed. They also go into flowing much quicker and finish up faster. On average by about 4-7 days or so.
The solution of course is more veg time. In veg the plants will grow right into the light without any damage but 36" is what they recommend. In flower I have gone 18-36.. Not sure I can tell much a difference. . However I have gone 100 organic so as soon as I get everything dialed in with the organics I will play with heights some more and do a side by side.
One thing I have noticed is in a tent I get better yields. I just redid my main room so I put mylar on all the walls and will see if that helps.
 
thanks for the input. im in process of redoing room. was planning on going with CMH exclusively, but eft some space for additional HPS. :)
 
X, you thinking of going with 315s or the 630 de cmh? I have a couple de 630s on the way, but also bought splitters so I can run 2 315s off the ballast if the de component isn't up to snuff. Will be interesting to get them dialed in.

a.
 
i got the 315s with the nanolux cloud control system. will be running 12 of them in a 10x14 space with 3 vertical 600hps if needed. still trying to figure out how to get to water plants on the back of the scrog. i started using blumats, but didn't like all the tubes on the ground. if i can organize the tubes i will use them - i am leaning towards the flora-flex system, but need to study a bit how it'll work best in my space.
 
@Boo

3' seems like a lot. aren't the 315s rated for a 3' area? At 3' from canopy you'd be at the outermost limit of the light intensity? My brain isn't use to this spectrum. At that distance the light doesn't seem that intense. I am going to get a PAR meter.
 
My plants don't like the 315's close at all, the leaves transpire and get dry any closer than 2'...they make a huge difference in my opinion when mixed with T-5's...I'm fighting heat issues so the flours help...the cake I posted up for POTM was cake done under the CMH's...I'm curious as to how the do in flower...
 
I have 6 of the DE 630 watt CMH units but alas have only been able to run 2 at a time due to electric issues in flower atm. I also have 8 of the 315 watt CMH of which 4 have never been used and tbh prolly never will be. The results I am getting from the DE 630's are pretty good, so far, but I think they could have been even better if more units were working in conjunction. I ran 9 one gallon pots and one 7 gallon pot. The buds were on the small side which i expected due to small pot size and slightly larfy if not in the canopy. I believe that the larfyness is due to there not being enough of these going at once to produce the necessary cross lighting to produce the nice hard nugs all the way like my DE hps do(did). If anyone is looking for a kit style 315 watt cmh system I have 4 spare brand new mogul style 315 watt CMH bulbs and low freq square wave ballasts for sale, all you need is a reflector and cords:D

2b2s
 
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