4x8 and 3x3 Grow Tents Lighting Question

[TurboGSR96]

Hello everybody,

Would 2 1000w hps's in a 4x8 Grow Tent be suffecient for max growth or could I squeeze another unit in there? I have not had much luck with CFM calculators if anybody can steer me in the right direction as far as a CFM figure goes to keep the ladies from burning up I would greatly appreciate it. I am about to order the tents but I want to get the lights at the same time. I was going to use the 4x8 for my bloom room and a 3x3 with 2 400w MH's will that be suffecient for vegging? I might even look into another 3x3 or a 2x3 if it exists for a cloning/seedlings can I just use floro's in there or should I a Halide in there as well?

I have all the basics down but airflow is a category I cannot seem to figure out and make a decision on, I dont want to have to buy stuff twice. Any help is appreciated.

 

[hemdigler]

lighting

as far as i have read you cannot feed them too many lumans... to a point, your only problem in a 4'x8' tent with 2 1000 watts would be heat. i was told a 600watt would be enough to do the trick. i would say that if you already have the lights you could do 2 4'x8' tents, unless you want massive cooling going. the vented hoods are ideal with a vortex fan for cooling it. then one more vortex hooked up to a air scrubber with a muffler and plug the vortex for the air scrubber up to a thearmostat to regulate the heat.... you want a muffler on it after the fan obviously, but one muffler makes a huge differance on noise, the fans are kinda loud, 2 mufflers is ideal for silence. anyone correct me if im wrong on any of that.

 

[diyJunkie]

Well, lets start with the 4x8 tent...
That has an area or 32 square feet - 1600 watts would give you a perfect 50 watts/square foot; so maybe a 1000 and a 600 in the big tent.
To keep that cool you want a fan capable of circulating air 2 to 5 times the volume of your room... Assuming the height of the tent is 6 feet... that gives you a volume of 192 cubic feet. since you have 1600 watts in there you are going to want to stay on the cautious side and move around 7-800 cubic feet per minute - so maybe get a separate fan for the hoods, and an 800 cfm fan exhausting the tent. Maybe 2 400 cfm fans

As for the 3x3 tent, a 400 will be fine and if it's also 6 feet you could do 2 fans, one for the hood and one for the room, or a larger fan to exhaust both room and hood. If only using one fan get about a 200 cfm and if separate get a 150 cfm for the room and a vortex for the hood.

Hope that helps some.

 

[dynamitejack]

If you want to run more than 1 light in a tent I would suggest getting nothing smaller than 8" cool tubes and a 8" fan to pull air from outside of the tent through the hoods then out of the tent. I think 2 600w lamps would do the trick, but it depends on the size of the plants you are going to grow. 2 600w lamps are going to put out 180,000 lumens, thats over 5,500 lumen per sq ft, 3,000 lumen per sq ft grows strong plants. If you are growing tall plants 4ft+ then I would do 3 600w hps lamps. I like 600w bulbs better than 1000 watt bulbs because the 600w produce more lumen per watt and also run significantly cooler.

For ventalation you want to exchange all of the air in the room 1 time every 3-5 minutes
192 ft3 room. 192/3= 64cfm then you need to add 20% more cfm because of the carbon filter, so 64+(64*.20)= 77cfm.

As for the 3x3 room 1 400w MH bulb puts out 36,000 lumen. 36,000/9sq ft = 4,000 lumen per sq ft. This is going to give you plenty of light until the plants reach about 1ft, then you can move them to the flower room. I would use a 6" hood and 6" fan to cool the 400w MH bulb.

Veg rooms don't put off that much smell, but if you want to play it safe:
2 of these: 1 for the veg room, 1 for the flower room.

1 of these to cool the 400w MH:
1 of these to cool the flower room lights:

and 2 of these to pull fresh air into your grow rooms, 1 for veg room, 1 for flower room:


Also you should buy an oscillating fan for each room. If you follow my advice you will have some danky dank dank buds like you have never seen.

read:

 

[l33t]

Use cooltubes or any other type of aircooled reflectors and use big fans. 8'' fans should do it , you can always use a speed controller to adjust the speed according to your needs .

For 3x3 use 600w or you can even use 1000w.But since you are gonna use this one for veg you can use a 400w no problem.. For flowering in 4x8 I'd definitelly go with 2 x 1000w.

Generally anything over 70w sq/ft should do it. I work with 100w/sqft and seems to be ideal with strains that love lots of light.

 

[cway]

I run 3400 W in my 4x8.. RUn as much light as u can so long as you temps are below 80.. anything over like 120w/sq ft is overkill imho..

 

[Asiatica]

3400w in 4x8!!!!

WOW!

How do you keep temps below 80 with that much power?

Peace and positive vibes
:character0025:

 

[tophmaster]

i would say 2 1000 watts is perfect i usually run 4x4 tables with a 1000w hps over each table with them 2 side by side with about 8-10 inches in between that was perfect. had like 550cfm sucking out and like 350 blowing in for just two lights change it when u bump it up higher though and probably add an ac at 4 lights depending on your climate i guess. damn i am oil faced

 

[TurboGSR96]

Thanks for the replies fella's, you have been very helpful so far :)

 

[surfguy1936]

its all about 2 600s on a 6ft rail

 

[selfhemployed]

i run a 4x8 tent with 2 1ks and a 740cfm fan with ambient temps in the room at 74ish the tent runs at 80 right below the lights and 73 at the bottom of the tent. It is like the freaking sun in there I have to wear sunglasses

cheers

 

[vagiboy1987]

Use the square meter calculation not sqft calculation. I personally do cubic ft to meters at a 3ft height because I'm not dealing with a flat plane I'm dealing with 3 dimensional plants here. Yes technically your plants are trained to a flat plain indoors but I compensate for depth of canopy as well and in rare cases use angled lighting (low light, supplemental, and different source from main lighting) to help evenly penetrate a thick canopy.think of your lights shining down, it does this even with a reflector in a sort of pyramid pattern, the farther the light is from the source the less intense it shines on the plant. By angeling lower powered lights to the canopy in these areas I can even out my overall light. Since light is coming in at a different angel I can reduce some of the minor shading from leaves. So if your plants yield X amount per meter squared, factor in your lights to meter squared. In a 36 sqft grow space you have a little over 3 sq meters so calculate your lights say if you want 600 watt HP's per meter squared you'd get 3 of them 1800 watts which is just 200 watts under 2000 so 2 1000 watt lights is more than enough but still within tolerance of your plants especially if using CO2