HPS, MH, Floros, Phillips Cermamic Metal Halide has 'em all beat.
- Thread starter ThatOneDude
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ThatOneDude
Well-Known Member
Lumens Lumens Lumens, CMH has less than HPS......but can you get an open reflector HPS or MH light this close to your canopy? It's SPD's that plants use, not Lumens. Plants don't have eyes, they don't care how bright the bulb is.
Have you ever seen the lights in a stadium at night, Hundreds of them to light the place up but can you get close and look at one, of course not, your eyeballs would fry, from your seat, your eyes see a lot less lumens because of the distance.
ThatOneDude
Well-Known Member
here are some random pics from another site where people are on to CMH growing. These are not my grow, just being honest!
This IS MY Dj Short Grape Krush Freak, I used it to test my new ebb&flow set up. It's been in there for a little over a week, before this, it was in my CFL box. I'm growing from seed so the other plants are in DWC so I can move them out until I know the sex. The system is being tested and adjustments are being made until I have have enough rooted clones to drop in it. It's about 25 pounds (50 Liters) light on Hydrotron so I can work in there easier.
skunkushybrid
New Member
Those clones need nutes bad. Good thing to remember about clones and one thing I've learned. They are as old as the mother they came from.
This is a sort of riddle for me still, only slight but i'm almost there.
Just because the plant is smaller does not mean it needs less nutes, it just needs less water.
7 days after potting up I've given clones a nute dosage of 1.0ec. I expected to see some burn, but there was none, in fact the little bastards were begging for even more.
I concluded from this that it is not so much the size of the plant that matters but it is mostly the age of the plant that counts.
Try upping your ec, slowly... see what i mean.
This is a sort of riddle for me still, only slight but i'm almost there.
Just because the plant is smaller does not mean it needs less nutes, it just needs less water.
7 days after potting up I've given clones a nute dosage of 1.0ec. I expected to see some burn, but there was none, in fact the little bastards were begging for even more.
I concluded from this that it is not so much the size of the plant that matters but it is mostly the age of the plant that counts.
Try upping your ec, slowly... see what i mean.
Sublime757
Well-Known Member
So I see a lot of talk about an advantage of a CMH being able to get vloser to the canopy than our beloved security of an HPS.
As you can see the bulb is about 8"-9" away from the canopy. Also there is NO glass between the bulb and plants. The tape measure goes all the way into my reflector and is about 1/4" from touching the bulb. 430W HPS Hortilux
"But Sublime, your grow room must be hot as hell?"
WRONG, MOTHERFUCKA! Lights on temp is 76-80, lights off 70-72. How do I manage this impossible feat? Unfortunately being a total badass, which I am, has no place in the growroom. Instead I ventilate. Air is pulled from the vent fan duct from my bathroom, piped through the attic, and exhausted through a pipe and out the roof.
Until I see more substantial evidence on CMH's, other than the half-ass post on the other forums, my closed-minded ass will remain safe and warm wrapped up in my HPS.
As you can see the bulb is about 8"-9" away from the canopy. Also there is NO glass between the bulb and plants. The tape measure goes all the way into my reflector and is about 1/4" from touching the bulb. 430W HPS Hortilux
"But Sublime, your grow room must be hot as hell?"
WRONG, MOTHERFUCKA! Lights on temp is 76-80, lights off 70-72. How do I manage this impossible feat? Unfortunately being a total badass, which I am, has no place in the growroom. Instead I ventilate. Air is pulled from the vent fan duct from my bathroom, piped through the attic, and exhausted through a pipe and out the roof.
Until I see more substantial evidence on CMH's, other than the half-ass post on the other forums, my closed-minded ass will remain safe and warm wrapped up in my HPS.
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Sublime757
Well-Known Member
ThatOneDude
Well-Known Member
That's a great setup....for someone that can/wants to do all of that but, I haven't seen to many others that want to go the extreme of cutting a hole in their roof's to vent heat out. A lot of people's grow rooms or cabinets are in basements. Instead of running a vent up 2 floors and cutting a hole in my roof, I'd prefer to look into more realistic options. It's great you can do what you did, but, it's not really an option for for the majority of growers.
natmoon
Well-Known Member
So far i still havent heard from phillips and i am still waiting for tom green to get back to me.
One definite negative i have discovered is that there is a substantial wastage in the 530-540nm range emitting a fair amount of useless green light,visible to us but useless as far as i know for cannabis leaves.
I have no idea if the actual flowers themselves can utilize green light or not but i know its no good for leaf.
Personally i think so far that these bulbs would be good for vegging if you only have a hps ballast or for vertical positioning amongst plants as a compliment to a normal hid lamp during the flowering phase
One definite negative i have discovered is that there is a substantial wastage in the 530-540nm range emitting a fair amount of useless green light,visible to us but useless as far as i know for cannabis leaves.
I have no idea if the actual flowers themselves can utilize green light or not but i know its no good for leaf.
Personally i think so far that these bulbs would be good for vegging if you only have a hps ballast or for vertical positioning amongst plants as a compliment to a normal hid lamp during the flowering phase
Sublime757
Well-Known Member
Umm I never cut any holes. I smiply tapped into the existing pipes going out the roof.
ThatOneDude
Well-Known Member
Growing in an attic or top floor? I don't know how big your grow room is but by venting out of the roof, do you have to use odor control? I'm in a cab in a finished basement of a 3 story house......no chance I can tap into something to vent out of my roof. But that's a cool set up to be able to keep those temps that low with the light that close to the canopy!
Sublime757
Well-Known Member
Yes, attic. An odor is controlled via carbon scrubber. I wish I had a basement I could grow in. But no, mine's full of mexicans.
ThatOneDude
Well-Known Member
I saw in your gallery, you had a 5'10" plant with that 430 watt light. You have a a lot more cubic feet to heat up then I do. I've got a total of 27-30 inches in grow height by 36 wide and 30 deep. 400 watts cmh with a 4 inch fan and carbon scrubber temps are running High 70's -82 degrees now. I cut a piece of white paneling and then cut out for the reflector in the center of that, mounted the carbon scrubber directly behind the light socket and vented it out of the cab into the ceiling. That was the best I could do to get the heat out. I'm thinking about modifying the opposite side of the reflector to fit a 120 mm, 93 cfm fan to blow directly on the end of the bulb blowing back through the other side to the carbon scrubber. If I can get to the mid 70's I'll be happy. Plants are not showing any problems at the current temps but the cab is not full yet either, I just started cutting the first clones so it's going to take a while.
Sublime757
Well-Known Member
Yeah those are very old pics. That plant went through 9 kinds of hell. But your setup sounds good for making due with what you have. And the 120mm fan idea sounds promising. I'd definitely try it if you're having heat issues.
ThatOneDude
Well-Known Member
Yeah......my old grows were with 2 600 watt lights in an open basement no air cooling needed, just floor fans and 4-5 foot plants in DWC buckets and CO2. It's been a big change for me switching to this cab growing, height, heat, and cramming all the crap into a stealth cab is new to me. Just got 2 new orders of seeds today. Serious' AK-47, Seedmans Alta Tunda, Mandala Safari Mix (left over $ on the prepaid card, not something typical for me) along with a haze/skunk freebie will be SOG style on about a 2 week turn time on clone to flower, DJ's Grape Krush will be veged for a while, not a good strain for SOG.
If you have any cooling ideas, don't be shy, advice is always welcome but no room for an ac unit.....I looked into Peltiers and thermoelectric cooling, but my hood stays cool all the way around so they wont help.
If you have any cooling ideas, don't be shy, advice is always welcome but no room for an ac unit.....I looked into Peltiers and thermoelectric cooling, but my hood stays cool all the way around so they wont help.
goatamineHcL
Well-Known Member
so do these bulbs have to be used in hps ballast or can you put them intoa a 400w mh ballast?
ThatOneDude
Well-Known Member
Only with an HPS ballast.
goatamineHcL
Well-Known Member
thanks hopefully well get to see a nie difference then i mioght pick one up
tsnow
Active Member
Man you might be able to do even better if your in an unfinished basement. Just vent out the sewer line. Interesting read, thanks for the post..