315w cmh

thenotsoesoteric

Shinobi of seeds
Pollen Chucker
I figured this HID section was looking a little lonely so far. Since I've traded in the old HPS for the 315w cmh I figured I'd start the thread.

Gotta say I regret not switching from the 400w has air cooled to the open hood 315w. I thought heat would be an issue but honestly the exhaust fan for the tent handles the heat just as good as the shitty air cooled hood.

I haven't really noticed a difference in resin production switching from hps to cmh, buds are a little more likely to foxtail with the cmh but still produces rock hard dense buds. I was also worried the whiter light might produce more leaf material but I haven't noticed any difference really.
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HydroRed

3Thirteen Seeds
I figured this HID section was looking a little lonely so far. Since I've traded in the old HPS for the 315w cmh I figured I'd start the thread.

Gotta say I regret not switching from the 400w has air cooled to the open hood 315w. I thought heat would be an issue but honestly the exhaust fan for the tent handles the heat just as good as the shitty air cooled hood.

I haven't really noticed a difference in resin production switching from hps to cmh, buds are a little more likely to foxtail with the cmh but still produces rock hard dense buds. I was also worried the whiter light might produce more leaf material but I haven't noticed any difference really.View attachment 1243
Ya, I was noticing the tubleweeds blowing through this area of the forum lol.
CMH is one of the few lights I've never run. I jumped right from multiple 1K MH/HPS to COBS. My 1K's still get a nice workout in cooler months and my garden still loves em! Do you find yourself needing more headspace between the light and the top of canopy with CMH vs MH?
 

thenotsoesoteric

Shinobi of seeds
Pollen Chucker
Ya, I was noticing the tubleweeds blowing through this area of the forum lol.
CMH is one of the few lights I've never run. I jumped right from multiple 1K MH/HPS to COBS. My 1K's still get a nice workout in cooler months and my garden still loves em! Do you find yourself needing more headspace between the light and the top of canopy with CMH vs MH?
No more head room than I ran with the hps. I like to keep the plants at least 12-18 inches above. Plus the white light is less of a security concern if people happen to spot some of that bright light leaking out a window or something. That old orange hps was a dead give away, lol. Well, I guess my 2700k quantum boards are pretty orange but doesn't seem as bad for whatever reason.
I prefer the cobs over the cmh personally. Cmh is a good light for intended purposes but IMO watt for watt it cant touch led
I was going to build a cob setup but have parts ship to me was an issue so I just went with the cmh because it all came in one box. To build the cob light I would have had to have 3 or 4 boxes shipped to me.

I do plan on building some nice set ups in the near future.
 
I used to swap my 315 in during the winter/colder months but I didnt bother with it this year.. Ive got a younger relative who's dropped a couple hints and I know from experience a 315 in a 3x3ish tent is a great little starter kit

No more head room than I ran with the hps. I like to keep the plants at least 12-18 inches above. Plus the white light is less of a security concern if people happen to spot some of that bright light leaking out a window or something. That old orange hps was a dead give away, lol. Well, I guess my 2700k quantum boards are pretty orange but doesn't seem as bad for whatever reason.

I was going to build a cob setup but have parts ship to me was an issue so I just went with the cmh because it all came in one box. To build the cob light I would have had to have 3 or 4 boxes shipped to me.

I do plan on building some nice set ups in the near future.
Didnt you just wire up a couple of those qbs fam?
 

thenotsoesoteric

Shinobi of seeds
Pollen Chucker
I used to swap my 315 in during the winter/colder months but I didnt bother with it this year.. Ive got a younger relative who's dropped a couple hints and I know from experience a 315 in a 3x3ish tent is a great little starter kit



Didnt you just wire up a couple of those qbs fam?
Yeah, I ordered a 2 qb kit I think it is like 240w or something like that. Thing is pretty darn bright. It destroys a 2x4 cabinet.
 

Capt C

Saltwater Cowboy
That is an awesome light!. I am using a 315 CMH and have a timber 2VL beside it (and my citi cobs). This will be the first grow i could run them all and not worry about heat.

So it is like the ghetto sport 515...
Thank you and yes on the ghetto sport 515... . I do have it on a mover as well. Rely feel like i could get the canopy closer have it down know around 16" with no issues. Very easy to construct just aluminum angle from the hardware store.
 

gwheels

Elite Hobbyist
Staff member
I am currently using the 4200 bulb (master color) to veg and will switch over to the 3100 bulb when we hit flower. This will probably be the only time i veg with the 315. My veg tents are too small for the light (20 x 36 inch base).

Have you used both bulbs in your CMH?
Which do you prefer full cycle?
I will run mostly 3k everything in flower but i have read mixed reviews about which bulb color works the best but the university of someplace said the 3k was ideal start to finish.
I had a tent full of 4k flowers and i prefer 3k for the buds. 4k seems to produce a lot more leaf so i will use it for veg.

On my second grow with my CMH hybrid. 315w CMH +4- 50w citizen cobs= The 515 sport. Would love to here some input on longevity of the CMH bulb

I have heard people going over 20k hours on the 315 and have had no appreciable change to performace. I am sure it is measurable but not enough to be a big deal.
And 20k hours is 4.5 years at 12/12.
 
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Capt C

Saltwater Cowboy
I am currently using the 4200 bulb (master color) to veg and will switch over to the 3100 bulb when we hit flower. This will probably be the only time i veg with the 315. My veg tents are too small for the light (20 x 36 inch base).

Have you used both bulbs in your CMH?
Which do you prefer full cycle?
I will run mostly 3k everything in flower but i have read mixed reviews about which bulb color works the best but the university of someplace said the 3k was ideal start to finish.
I had a tent full of 4k flowers and i prefer 3k for the buds. 4k seems to produce a lot more leaf so i will use it for veg.
What a bargain compared to HPS bulbs
 
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