Can I use 70w metal halide over 1 sq ft?

[m00nchild]

I have a very nice fixture that I used to use over an aquarium. It holds a double-ended metal halide bulb at 6500k, 70 watts. Over an aquarium it just looked like pure white light.

I am building a small (25"x13"x11") micro sog cabinet right now, and I'm at the point where I need to choose my lighting. I see many of the benefits of using CFLs, but I figure, since I already have this one light, can I just use it? Is 70w of metal halide power good enough for this type of cabinet? The reflector is very nice, too, so there would be no wasted light:

Does anyone think it's worth my time, or should I just put a handful of CFLs in there?

 

[j.guit.err]

Depends on your ventilation setup, what's that look like?

 

[cork144]

Hi, for my 1sqft cab im going to be using a 70watt hps,

ill tell you how im going to be setting up my cab to vent all the heat, remove the odor, and grow great nugs.

Firstoff find some sort of bendable metal sheet, cut it to the depth of your cab, and 4 inches wider.

find the middle of the sheet, mark this down, then from that point mark either side of it for half an inch, Draw lines up these points so you have a inch wide collum drawn out, bend the reflector at these points to the angle so that they will now fit into your cab width wise.

Get your light fixture and attach it to a peice of metal, bend it so that your bulb with have about 1 inch clearence from the top of the reflector, bolt this onto the reflector and install into the top of your cab (drill holes in the collum and screw into the top of your cab.)

This might sound excessive, but get ahold of 8 80mm pc fans and 1 120mm pc fan.

To build the fan, Cut 2 flat peices of wood to the dimensions of 220mm Tall X 220mm Wide, Cut 4 holes into this where you wish to place the exhausts of your pc fans, in these places stack 2 pc fans ontop of each other and secure them to one of the wooden faces with a bolt running through the wood and through the pcfan mount holes, do this to every fan untill you have all 8 pc fans installed with 4 of them exhausting and the other 4 pushing into the exhausting fans, neaten up all the wires so that they leave through a single hole, feed the wires through then try your best to seal that hole up.

You now need to cut 4 wooden peices so that the 220mmx220m pannels will secure onto them flush without any overhang(sorry but i cant realy tell you the dimensions you need to cut because i dont know the width of the wood you would be using lol)

Build a carbon scrubber, i suggest the mesh pencil cup scrubber which is in the DIY topic, posted on sugarbears topic.

To now what ever the dimensions of your scrubber are, you now need to make that sized hole in the back of your cab, and into the un-used 220mmx220mm pannel (make sure the holes in the center!), i suggest making the hole in the cab about 15cm down from the top of the back wall so that your fan wont be popping up over the back of the cab.

Attach the single 120mm fan somwhere so it will be blowing onto the bulb but not stopping anylight from getting to the plants (im probably going to cut ahole in my reflector for that)

Once its done, youll have a slightly slopped reflector (allthough you can make the slope sharper by increasing the width of the metal sheeting so you have to bend down further) With a 70watt HID, 110CFM fan through a scrubber with good torque to pull through the scrubber, depending on how well you make the scrubber determines the quality of the filtration.

My cab will be setup like this within the next few months, allthough im considering 2 70watt HPS lights and building my fan using 8 120mm fans.

 

[catman]

Are you trying to keep noise down cork?

If so.. I just wanted to let you know that my Panasonic whisper 80cfm fan makes noticeably less noise than a single 80cfm 120mm PC fan. PC fans aren't well suited for a carbon filter and sure it can be done, but the fan's motors often die out and even create excess heat when over worked!

Use this formula to help decide how many CFM you need.

CFM needed = (3.2xWATTS)/Difference in Temp desired above room temperature

 

[m00nchild]

For ventilation I'll be using passive intakes and probably a 4" inline fan for exhaust. I'm not in super need of stealth either, so I'll probably not be dealing with a carbon filter. My house smells like smoked cannabis all the time, anyway, so I'm not concerned about odor.

I'll also be separating the light from the actual growing quarters with a sheet of plexiglass. This blocks a tremendous amount of radiant heat from the lamp in my experience.

Heat won't be much of a concern. I'm just wondering whether people think good bud can be grown under 70w of mh light.

Thanks.

 

[cork144]

yea they can, no filters isnt realy smart.

youd be better off not using the glass and just cooling it by having your inline fan inlet neer the bulb.


pc fans tokeep cost down, costs me about £15 to make this fan, and £2 a fan for if any blow.

 

[organicmunk]

i would supplement the 70 watt with two 26 watts thats what im planning on doing any ways computer fans are fine for those on a budget hey thats what i use i run no scrubber but i have these scented things there pretty sweet i stick one in my cab and you cant really smell anything its like a masking agent sort of but lets just say my land lord was in my room 3 time half way through flower and the cab was running full blast didn't hear or smell a thing i think thats good enough for me

 

[smokeymacpot]

For ventilation I'll be using passive intakes and probably a 4" inline fan for exhaust. I'm not in super need of stealth either, so I'll probably not be dealing with a carbon filter. My house smells like smoked cannabis all the time, anyway, so I'm not concerned about odor.

I'll also be separating the light from the actual growing quarters with a sheet of plexiglass. This blocks a tremendous amount of radiant heat from the lamp in my experience.

Heat won't be much of a concern. I'm just wondering whether people think good bud can be grown under 70w of mh light.

Thanks.

it may well be possible to get 1-2oz from it if you do a scrog.

 

[funk_buddha]

Done it in around 1.5 sqft with a good 2 gal rez/cooler. Do it.

 

[White]

Don't use it, you'll die.

Jus kiddin man,

Whatevers clever

If you're worried about not enough light, supplement it w/ a couple of cfls. If not, then stay w/ your 70W. As long as heat aint a problem, I'd go balls to the wall with lightage.

END DRUNK POST

 

[organicmunk]

dude im using a 70hps and 2 26 6500k cfl cooling the whole cab with one 80mm fan and my temps are 3 about ambient the high last night was 76 and i have 1.2sqft so thats almost 120w per sqft i would say go for it its alot of heat but far more penetrating than any CFL

 

[m00nchild]

Okay, so I think I'm going to do it! The cabinet I have gives me 2 separate grow spaces, each one is 13"x11". One will be for mothers/clones, the other will be for flowering. In the flowering cab I'm putting a 70w MH. In the other one I'm putting 4x23w CFLs.

What I'm going to do for my first run through, where I am planting seeds to select my mothers, is run both cabs side by side all the way through flowering. This will give me an opportunity to compare the buds from all CFLs and all MH. If I see that the MH blows the CFLs away, then I'll keep it! If not, then I'll replace it with 4 more CFLs.

After I harvest the buds and smoke 'em, I'll reveg the chosen few, and go on to use one cab for veg and one for flowering. I'll have a grow journal soon, hopefully, so people can see my results. The cool thing about this cabinet is, it takes place inside an aquarium stand, with a fully working aquarium on top! The aquarium provides stealth in numerous ways, from covering up sound to covering up bits of light leakage from inside the stand... but the most important way is that once people see the aquarium, it's what they focus on, so no one even begins to think that something else is going on. It's the old "create a diversion" technique, lol.

Thanks for all your help, everyone!

 

[m00nchild]

Oh yeah, by the way, I took everyone's advice on the PC fans and decided to go with a pair of 120mm fans in each half of the cab. My preliminary tests have shown (in the CFL side, anyway) that the PC fans are keeping temps just a few degrees above ambient! PC fans are awesome!

 

[kii]

if my memory serves me right thats a 70watt diy hqi from hellolights.com? glad to see another nano reefer playing around with herb.

as far as growing with it I dont see much of a problem either than heat and height either than that go for it you don't have much to lose.

 

[m00nchild]

Guilty as charged! Except it was just the reflector I got from them. I got the ballast and bulb someplace else.

I've been doing reef tanks my whole life, and it just now dawned on me how that hobby and this one could merge together, lol! And yeah, I figure, I already have the light, so it will cost me nothing, so I might as well go for it. If it gets too hot or whatever, no big deal, I'll just go with CFLs next time.

Thanks for the warm welcome!

 

[organicmunk]

i would go buy a piece of plexiglass to separate the cab from the light if you get what im saying thats what i did and i run 1 80mm pc fan with a 70hps and 2 26 watt cfls

 

[inefectualize]

another nano reefer here ... funny how that can be used two ways... might want to throw one or two warm kelvin compacts in there to balance out the light.....i have a cab about the same size that i run 2 x 70 watt hqis and 2x 13 watt cfls......let me see if i can figure out the picture thingy...

 

[organicmunk]

inefectualize: thats one crazy fish you got there

 

[m00nchild]

Awesome! So what kind of yields are you getting under those lights? And what k spectrum are your HQI bulbs?

 

[inefectualize]

the k rating is 10,000 k......i dont put much faith in k rating.....they do look blue but more like a crisp, crisp white....my yellow cfls balance it out to what i perceive as a 6500k....i have never flowered under this, i just get stuff started in here....the hqi's i think give off a good bit of uv (complete conjecture) but the plants stay short and develop very strong rigid stems.......pretty intense light