HID Lighting discussion

videoman

Hey people, I just felt like doing a basic review of lighting here.
There are all sorts of lighting available, especially if you really look.

When it comes to High Pressure Sodium lighting, for this post we are mainly talking about either, the 400watt model, the 600 watt model and the 1000 watt model.

The 400 watt produces about 50k lumens
The 600 watt produces about 100,000 lumens
the 1000 watt produces about 150,000 lumens

Part of the decision process involves facts that only you know about your grow. Aside from those facts and purely in my opinion, if you have an "open" decision on which light to get.....

The choice becomes obvious as you do the math.
The best bang for the buck is the 600 watt model.
You get 100% more light than the 400 watt model for only a 50% increase in watts.

If any of you want to engage in an open convrsation, debate, comment or post questions, feel free.
Peace

eyemthatguy

I like the thinking about the 600, right up until I start thinking about heat. Can anyone ballpark the heat increase to expect?

I know I had enough trouble this summer keeping my area cool and supplied with fresh air. I mainly use fresh air from outside filtered through nylon stockings. On the especially hot days, we ran a/c during the day and fan at night.

Now this really might be an option in the winter months when I plan on exhausting carbon filtered air into the rest of the living space.

Who woulda thought, Im beginning to think about using more power in the winter to increase yields enough to tide me over through the summer.... right now its just a thought.

*Edited to add*... cant believe I forgot this in the first place. Seriously can you expect to double yield when you double lumens? Whats a reasonable example, if one can be given...

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Fman

EYE- Im thinking the same thing. I got a 400hps lighting a 3x4 space. There is a 171 cfm fan with breadtube cooltube fixture. Temps were just at the limit ,around 85-87 most days, that being said a 600 would be too much for my space, without a much larger fan.

Vid- would a 50% increase in watts bring a 50% increase in heat?

videoman

eyemthatguy and Fman.....
We all need to make sacrifices and trade offs along the way of our decision making process. heat is our enemy...along with LEO

Normally, and in my opinion, you need about a 500cfm quality fan for one 400 watt light. Now here comes a trade off, I run two 400 watt lights presently, (I am about to upgrade one to a 600 watt this week) I use cooltubes and run the lights connected to each other, I pull air through them, rather than push the air, and I use a fan that is about 500cfm it does work. On the hotter days, I wish I had more though.

In my favor, since my grow is vertical, my air is picked up at almost ground level, where the coolest air is, as heat rises.

Fman, you should thing about getting a better fan. I had one of those bread pan cool tubes last year and was not happy with it, the bread pan is not as wide as a real cooltube so air becomes restricted.

More lumens equals bigger and better buds.
Peace

eyemthatguy

Fman,

sounds about the same.
2' x 4' x 5 ½' space
4" can fan 155cfm - rs-4ho
hydrofarm xtrasun 6" air cooled reflector
6" ~> 4" converter
4" ducting @ 6 feet total.

I was using a diy cooltube with a crappy reflector and 80mm computer fan along with the rest up there, and noticed a 7-10 degree change when i changed to the air cooled xtrasun reflector. I see more even light distribution as well, for what its worth.

600 would be nice if I dont have to buy a new can fan...



Vid,

how the heck do you control the noise on a 500cfm beast?

__________________
Fungus Gnats moved into your grow room? No problem.

Fman

My air is boosted from under the house ,then drawn thru the tube with the 171.
In most of the reading and reasearch I've done the PROS all use 1000, cause thats where the biggest buds come from. Plus most have them on movers so they can keep them close to the plants, without burning . Like you say though ,trade offs, all that takes, more space, more money,and more electricty, BUT of cource that gets you bigger BUDS. Im happy with my 400, Its a big step up from the cfls I used last year, More lumens at about the same watts, and only a little more heat.

videoman

Dude, why the reducer? your hurting yourself by doing that.
I dont use reducers, and try to make as few bends as possible, and when I do..I make em gentle.

The 500cfm fan is very quiet, I got it from hidhut in fact, with the door closed, and you standing outside the door, you cant hear a thing.
I leave the fan on 24 hours a day.

The 1000's will always produce better buds, if you can afford to run em.
I am slowly moving to 600's, but no matter even with a 400 watt light, you can grow some kick ass buds.

I've had many a cured cola weigh in at 30 to 35 grams after curing. So those colas were about 100 grams or so at harvest.
Pick the right strain, and make sure you veg long enough.
5 weeks in my opinion is a minimum.
Peace

4kaan4

I have heat issues, also. I use a 400w for intermitent side light. It is cooled with a 260(?) cfm fan drawing air from the room and exhausting it out of the room. I use a 4ft 4 tube t-5 floro for constant top lighting. Heat is kept under control by allowing cool air from outside the room to seep in, replacing air taken by the fan. I have enough space for a 600w, but not enough ventilation. If I could remodel the house (anyone seen any money laying around lately?) I could fix up a completely closed venting for the light and be able to use more watts.

Later,
4kaan4

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videoman

Oka, lets discuss heat and air exchange for a bit. There is one rule that says to replace the rooms air every so many minutes, obviously I ignore this rule, as heat reduction is way more important, and if you tackle the heat properly you'll replace the rooms air an adequate amount of time to introduce new co2 into the room.

Having said that here is the rule of thumb I go by, and its been around for a dogs age:

Lets assume a typical 400 watt light using a 500 cfm fan....
Take 3.2 and multiply that by your watts (400)
3.2 x 400= 1280 now take your answer, 1280 and divide that by your cfm
1280/500=2.56

This tells us that using a 500cfm fan will raise our growroom temps by about 2.5 degrees over the rooms ambient temperature.
Peace

Fman

I used that formula. Thats why I got a 171cfm fan . 1280/171= 7.48 , The temp. of the air under the house is about 70 to 73 most of the time, so i figured 73+7.5= 80.5 ,thats a nice temp, and the 171 was all I could afford. Unfoutunatly temps got to about 75 to 78 under the house this summer, SO my room got hotter.