Help me pick a light

[varriform]

Hello all
I have a Darkroom80 by secret jardin which is basicaly 2.5ft x 2.5ft x 5ft on the inside. I am trying to figure out what lighting would be best for this setup. I have a 175cfm fan and an elf filter. I already have 2 150w hps lights that I have been using but I am looking to get rid of them because they are not very practical in a tent as they are built in ballast fixtures.
What I am wondering is if I should go with a 400w or 250w light?
Digital or not?
Air cooled reflector?
I would like to go with the 400w just because I will be moving in about a year and might end up getting more room to work with, but I don't wanna be wasting light and battling unneccessary temps for no reason.
Any opinions are appreciated

thanks....peace

 

[Guest]

My vote is for a 400W in a cool tube.

 

[Retardo Motabon]

Go 400w. To date, my favorite hood, by far is the super sun 2 hands down. However a more square hood might do better for 2.5 square.

 

[varriform]

Cool, thanks
Will a digi cool it down at all?

 

[Retardo Motabon]

I know nothing about digital ballasts but your bulb will run the same temp whether the ballast is digital or not. Air cooled will help alot. I know it's a piece of cake to repair magnetic ballasts for chump change but if a digital goes down, your either buying another light waiting for repair unless your shop will trade out. With a 400w you'd be just fine with a 4" ducted hood. 400w switchable mag ballasts are pretty cheap too.

 

[varriform]

Thanks
Thats what I heard but I thought I might save some electricity.
Everybody agree on the 400w?
If so, anybody know where to get one with a air coolable reflector?
thanks
peace

 

[varriform]

If I use an aircooled reflector will I have to have a seperate system for exchanging/scrubbing air in my growroom?

 

[andrew415]

Go with the 400w with maybe a cool tube if you cant keep it within good temps without.

Thats what I run anyway (400HPS cool tubed)

250W is just as hot so you might as well go with the 400

good luck

 

[Climbinghigh]

I agree^^, 400 is best for that space, but must be air cooled and well ventilated because it will get hot- get a good blower and rock it!
Plus if you decide to expand later it will be easier if you already have the 400 instead of the 250. And in the short term, the difference in yield will pay off.
Good luck and stay safe.

 

[varriform]

Cool thanks
400 is like the same price anyways. I could just use an aircooled reflector instead of a cooltube right?

 

[varriform]

Would I need more than my 4inch 175cfm fan and my filter? besides a regular fan that is.

 

[Climbinghigh]

I decided to go with the big square Sun System hood even though it only has 4" flanges because i wanted even light coverage. I run a blower(with no filter though) that's about 175cfm and in the winter it's been cool enough to take the glass out- but in the summer I hook up the intake going into the hood to a widow AC unit. It's still too hot in the closet to close the door if the lights are on and i have a big box fan hanging in the doorway.
High temps and low humidity are a constant battle for the space I have-Ce la vie!
I think you should put that equipment to use now and see if its going to work- if not- improvise, thats what illegal growing is all about Peace, luck, and safety

 

[Hawk]

Anyone know how many BTU's each size lamp puts out? Sometimes I feel that would mean more to me than anything else. I figure there's so many variables specific to each person's experience with 250 heat vs 400 heat that it's really hard to nail anything down.

I'd love to see a somewhat controlled test on the heat difference of a 250 vs. 400. Maybe air cool two otherwise identical arrangements (space, ambient temps, hood type, etc) and take some measurements. Perhaps even pull 150, 300, and 450 cfm over each light and see what happens. It would be interesting to find out something like: when air cooling at 150cfm the 400 is substantially hotter but if you cool both with 450cfm there's hardly a difference. Hell, if there was more than one light fixture on hand test those too. Maybe we'd learn that some combos of hood and cfm will cool each similarly while other hood/cfm combos cause a spike in temps once you step up to higher wattage. Know what I mean??


If I had the equipment to design and execute such a test I would....(hint hint).


Since I can't find that kind of testing, I think Climbinghigh's comment is on point. Ya just gotta take your best guess and see for yourself what works for you and take it from there. It just sucks cause trial and error is rarely thrifty.

$0.02

 

[varriform]

Sweet thanks
I'm thinking a 400w running a CMH with some sort of air cooling. Man this is alot of thinking, I have always been a somewhat simple grower. Anyways, I'm still taking peoples suggestions and thoughts.
Peace

 

[summitoker]

400 in a aircooled hood

 

[FreezerBoy]

At 2.5 x 2.5 a 250 is slightly undersized (Watts=SqFt x 50). In a cab that size a 400 will definitely need air cooling. A 175 CFM fan should handle the bulb (CFM=Watts/4) and will probably handle a scrubber as long as it's the right size for your fan and your ducting isn't too long. Before rigging a separate vent system for the scrubber, try this: Hook the scrubbers exhaust to the hoods intake vent. Air goes through the scrubber, through the hood, through the fan and out the cab.

 

[varriform]

Hey thanks,
That seems like a pretty good idea.
Could I go in this order? With air being passively sucked through a reflector with a fan on one end and just open on the other?
Air in room > Reflector > Inline fan > Filter > Short ducting out of tent
Not sure if that would work
thanks peace

 

[varriform]

I suppose it's about the same thing.
Which is more practical or manageable?

 

[FreezerBoy]

Better to pull than to push. Fan should go last. Filters I'm familiar with are can shaped. Closed at one end, drawing air through the sides. These can't go in the middle. They have to go on either end and, better to pull than to push. Do they make "inline" filters as opposed to "end of line"?

 

[varriform]

oh yeah
cool thanks