Advice on HID lighting - 600 watt? Or 1000 watt dimmed to 750?

growstrong

New Member
So I am slowly building up for my first grow and need some advice on lighting. I am going to be growing in a 4'x4'6.5' grow tent. I will also be using a 6" inline fan(with speed control, phresh filter, and vented a few feet out window) and my room stays around 72-76 degrees year round. (AC in summer, heater in winter.) I am trying to get as close to that magic 50 watts per square foot number as I can. So if I get a 600 watt light, which everyone seems to agree is the most efficiant wattage it will give me 37.5 watts per square inch. not bad. But if I get a 1000 watt light (which is dimmable) and down it to 750 watts, that would give me a magic number of almost 47 watts per square inch. In your opinion, what would you do in this situation? and what is your reasoniong?

BTW I will be running MH for veg and HPS for flower on this same light and more than likely be aiming at a scrog grow.
 
I don't know why there is even a debate. With the dimmable 1000 watt you can run 600 watts, 750 watts, or 1000 watts. I have a 4'x4' tent with a 1000 watt dimmable ballast. My room stays 70-72 degrees. I run it at 75% and usually temps in the tent run about 80 degrees.
 
Let the temps tell you how to run it, not us :thumb:

I run mine near 30C around the canopy. Too hot for many but not for Vlad. 12/12 day 4

You may want to start out at 26C around your canopy or a little less if in veg. Depends on your strain too.

IMG_024347.JPG


V:bongrip:
 
The only downsides I have heard of is heat issues and bulb life being shorter with dimming really. I think I will be able to deal with heat, and bulbs I don't have a problem with changing every 2-3 grows if need be. But I would like to hear from all of you with actual experience.

Thanx BrixNewb!
 
This is my thought. If I use a 1000 watt and turn to 50% at start of veg, It would give me an idea for heat issues. 50%, and if all good 75%, if all good, then full power. Makes sense right?

Let the temps tell you how to run it, not us :thumb:

I run mine near 30C around the canopy. Too hot for many but not for Vlad.

You may want to start out at 26C around your canopy.

IMG_024347.JPG


V:bongrip:
 
The only downsides I have heard of is heat issues and bulb life being shorter with dimming really. I think I will be able to deal with heat, and bulbs I don't have a problem with changing every 2-3 grows if need be. But I would like to hear from all of you with actual experience.

Thanx BrixNewb!

Not sure on the heat issues, I can't seem to run 1000 watts but 750 works fine for me. I heard of bulb life being shorter as well, but I figure I will deal with that once it comes up. Hortilux bulbs are only about $60 so it's not a big deal in my opinion.

I run a Phantom ballast which dims to 60%, 75%, 100% and overdrive. Been thinking about running it at 60% and the supplementing with LED in the 4 corners. Have to see if heat will be an issue.
 
Hey! just thought i'd chime in here..

I am currently running a 600W HPS @ 100% in a tent of similar size (3'11x3'11x6'7) and my temps are running 75-78F with ~50%RH and indoor ambient temps 64-68F; i run a 6" intake from a nearby window pulling in 48F outdoor air thru one of the 8" side ports during lights on.

With my setup as it is, i don't think i could get away with a 1000W, even at 75%, but, if you were to run 2 independent exhausts and ran cool air through your hood, then it would probably be more feasible.. I only have 1 exhaust system that also cools the light
(scrubber -> fan -> hood -> exhaust) but have already planned to next time at least put in a Y connector and bring in some cooler air for the lights..

I've read about the w/sqft thing too, but for me, I'm glad i went 600 instead of 1000 for the above reasons, but also for savings in cost; if more light is needed in future, can always add more 600's or LEDs.

we're I to use a larger space, i'd probably still go 2x600 instead of 1x1000; but there are many, I'm sure, who would not as well.

good luck!
 
I'm not tooooo worried with the electric bill. I am paying just about 17 cents a kwh, So I am looking at around a $100-$125 a month while running on an 18/6 schedule, and that drops even lower on a 12/12 schedule. I mean it could always be better, but it's not outrages.
 
How about a digital variable ballast? That would give you "options" in the future. A 600W run at 100% will likely outperform a 1000w run at 750. I reccomend a ballast that will run 400/600/1000w and cool tube. Only issue is you MUST be sure to use the correct bulb at each setting. Even at 600W, you'll warm up a room in 18hrs. You will need a plan to exchange are not only in your tent but also in your room. Good luck!!!
 
Alright. I think I might have the solution. How about 2 6" inline fans for cooling the full 1000 watt cool tube light and tent, separatelty.

1'st fan 440 cfm adjustable: 75 degree room-ducting-cooltube-ducting-fan-ducting-out window

2'nd fan 440 cfm adjustable: Carbon filter-ducting-fan-ducting-out window

In theory this seems like I would have a full 1000 watts at a manageable temperature right?
any thoughts on this plan?
 
Yes, as crazy as it sounds, blowing your bulb is the only way to get passable results.
I get my bulb down to 48C at its glass envelope and I run them open, not enclosed , it's 150W
You would have good results with water cooling but I have yet to see anyone make one and do a journal with it.

Vlad:bongrip:
 
Thanks guys. I think this might be the plan then. I have a couple more weeks till I start building, and will let you know how it works. I figure if temps are still too high I can bump the wattage down to 750. :)
 
I run a 1000w cool box system but I cut a square hole slightly smaller than the dimensions of the cool box fixture at the glass and raised the top of the fixture out and above the tent. I then attached a single 6 inch ventilation fan at 350cfm and hose to the fixture. I run a separate variable speed fan for tent ventilation. Running at 100% or higher power levels i have zero problems with heat. Sometimes have to slow my tent vent down to retain heat on clod days.
 
I run a 1000w cool box system but I cut a square hole slightly smaller than the dimensions of the cool box fixture at the glass and raised the top of the fixture out and above the tent. I then attached a single 6 inch ventilation fan at 350cfm and hose to the fixture. I run a separate variable speed fan for tent ventilation. Running at 100% or higher power levels i have zero problems with heat. Sometimes have to slow my tent vent down to retain heat on clod days.
Good info, but a 6 year old post. (Don’t worry it happens to all of us) Welcome to the forum!
 
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