# how many lights?



## sandman (Jul 15, 2006)

Hi there!
I have a space I'm going to start a grow in.The measurments are 7ft.deep,6ft.wide,6ft. tall.
I already have a dayton fan for intake and a bathroom fan for exaust.What size of lights will I need?How many?
The room was used before by relatives,but now it's just storage.The wiring is already in as well. Any help would be great!Thanks!
P.S.Is a bathroom fan for exhaust too small?


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## astra007 (Jul 15, 2006)

well, its said that ya need 3 sq ft per plant unless you are planning s.o.g. so you got 42 sq ft = 14 plants.  you can plan 50 to 80 watts per light so at a minimum of 80w x 14 = 1120w  or a 1000w HPS and a 400w HPS or 2 - 600w HPS.  With 50 its only 1 - 1000w HPS or MH. The difference in wattage will reflect the time to grow out yer plants completely.  you can pack in more sativas as they dont bush out like indicas and go 2 sq ft per.  thus getting 21 plants = i would go with 1 HPS and 1 MH 1000w mounted 3' from plant tops.  any1 else?


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## Stoney Bud (Jul 15, 2006)

sandman said:
			
		

> Hi there!
> I have a space I'm going to start a grow in.The measurments are 7ft.deep,6ft.wide,6ft. tall.
> I already have a dayton fan for intake and a bathroom fan for exaust.What size of lights will I need?How many?
> The room was used before by relatives,but now it's just storage.The wiring is already in as well. Any help would be great!Thanks!
> P.S.Is a bathroom fan for exhaust too small?


 
Hey Sandman, nice sized room to grow in man! You'll see lots of numbers for lighting lumens per/sq ft, but they will all be between 3,000 and 6,000. Pot will grow ok under 3,000 and even as low as 2,000, but not as well as 6,000. How much light you need depends on the strain you're growing, the reflectors you use, the distance from the surface of your plants, the general health of your plants, the type of nutrients you use and more.

I calculate for 5,000 lumens per/sq ft, and I use 430 watt HPS Hortilux bulbs at 18 inches. For my hydro grows, that works really well.

You have 42 sq ft of area in your 6 x 7 room.

Lets calculate for 5,000 lumens per/sq ft

5,000 x 42 = 210,000 lumen output is what you're looking for as a total.

A 430 watt Hotilux produces 58,500 lumens.

210,000 divided by 58,500 = 3.6 bulbs you would need to produce 5K Lumens per/ft, or say 4 lights.

This works very well actually. You can use four 430 watt bulbs and get great coverage in your room. The positioning of your bulbs should be so that at 18 inches from the tops of the plants, the light reaches just to the edge of your crop and a little on the wall. This should make all of them overlap some in your room. That's perfect. Position and hang your lights before putting anything else in the room. It'll be way easier to see and move. I would also suggest using the "bat-wing" reflectors. They have a great throw and would work very well in your room. 

Paint the walls with the brightest flat white paint you can find. Ask a paint store guy for the brightest flat white, he'll know his stock. I use "Behr" Premium Plus Ultra Pure White #1050.

Is the room airconditioned? Are you growing with dirt or hydro?

Tell us about how you intend to grow and what strains if you can.


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## astra007 (Jul 15, 2006)

hey great way of doing the math and conversion.  mounting with batwings means horizonal lights too. you can get closer to the plants with 430's too.


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## sandman (Jul 16, 2006)

I plan on using dirt to grow in.No the room is an outside shed so not air conditioned.I have a powerful dayton fan for intake and a bathroom fan for exhaust.I'm not sure if the exhaust venting is adequate if I run 4-430's.That's alot of heat!The walls and ceiling are covered with heavy white plastic(black on the other side).I may partition the room so I can keep a mother for cloning.I also want to find a good watering setup.


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## Stoney Bud (Jul 16, 2006)

sandman said:
			
		

> I plan on using dirt to grow in. No the room is an outside shed so not air conditioned. I have a powerful Dayton fan for intake and a bathroom fan for exhaust. I'm not sure if the exhaust venting is adequate if I run 4-430's. That's a lot of heat! The walls and ceiling are covered with heavy white plastic(black on the other side). I may partition the room so I can keep a mother for cloning. I also want to find a good watering setup.


I don't know what the normal temps are for your area, but you'll need to keep the shed within the proper temperatures while providing enough light for your plants. If you intend on using the entire area for plants, you'll need those four lights to maximize the lighting for your plants.

Hick is one of the best dirt growers on this site. Mutt and Bro Grunt are also both seasoned dirt growers. They should be able to help you iron out the best possible variables for you.

You can also use a reservoir and slow drip system to water your dirt grow. The drip has to be carefully monitored and can cause catastrophic failure if your pump fails, but it's one way of watering. I would suggest the old fashioned way of watering by hand every day.

Good luck to you man!


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## astra007 (Jul 16, 2006)

pick up a garbage can with a lid, any size to fill with a garden hose.  you can hand bomb from this or add a pump to wand feed/water.  put the lid on when not using to cut humidity.  remember to add yer ferts first then ph when feeding.


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## astra007 (Jul 16, 2006)

1 trick outside shed is to split ballast the shed.  by putting the ballasts on a timer and running 2 - 24 hours, you can split the room in half and run 2 lights 1 side while the other is dark then visa versa.  by putting a 2 way fan in the curtain/plastic to move the hot air from side to side will keep the temps up and cool the other side.  only need 2 ballasts but 4 lights.


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## Hick (Jul 17, 2006)

astra007 said:
			
		

> 1 trick outside shed is to split ballast the shed.  by putting the ballasts on a timer and running 2 - 24 hours, you can split the room in half and run 2 lights 1 side while the other is dark then visa versa.  by putting a 2 way fan in the curtain/plastic to move the hot air from side to side will keep the temps up and cool the other side.  only need 2 ballasts but 4 lights.



Astra..I believe that I follow your thinking here, but wouldn't that work _only_ if you're running 12/12 on both sides?..That idea eliminates the possibility to veg or clone. If 2 400's are running on one side for 12 hours for flowring, there are only 12 hours left in the day ro run the other 2. I'm certain you can't run 2 400's off the same 400 watt ballast at the same time. 
  If you ran 18/6 for veg, you would still need to run _all four lights_ for 8 hours p day.


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## astra007 (Jul 17, 2006)

yes your right.  this trick is for flower only.  as he only has 1 location, i assumed that he could run his veg/clone on 24/7 for a set time then go to flower time.  i have a friend in northern canada who does it this way.  sam runs 2 lights for veg 24/7 for 3 weeks or so then turns on his timer 12/12 to activate the flower cycle serving both rooms.  but cannot do both at the same time.  you could isolate a small section of the room for a separate 18/6 single veg room; like a closet.


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## Hick (Jul 17, 2006)

I see. A sure fire trick to utilize a single ballast and cover twice the area in flower. I like it..


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## sandman (Jul 17, 2006)

Thanks alot for all the info! What I may do is use a completley different space for a veg room.I'll  only need one mother,so it won't have to be too big a space.I would like to utilze the 6X7 room for flowering. Maybe a dozen plants? Now I only have to get the lights and ballasts.I may get a MH light for veg.At least I have my one plant in a greenhouse right now while I plan the indoor grow.


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## astra007 (Jul 17, 2006)

sandman, check grow stores for used ballasts as they either work or dont. but only buy new lights.  you can clone and veg under a 600w HPS.  i have 1 set up as a portable kit that i can move if need be.  a 600 hortilux bulb will give you 85,000 lumens and you can long veg up to 12 moms under this.  by kit, i mean light, ballast; all wired 110v in a metal box with handle.  i got 16' cord to light and 12' of cord to plugin.  put it in a closet or under house and away ya go.


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## astra007 (Jul 17, 2006)

ya can do up to 21 in that space in 2 gallon containers - if you are cramped fer space look fer square pots and get hardwall nursery pots as they are wash 'n reuse.  pick up a bottle of concentrated lime/sulfer - no oil and use 1 cap per 2 liters or 2 quarts - spray your seedling or clones beginning of the dark cycle with a fan running.  - will prevent mildew.


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## greenear (Aug 9, 2006)

I am a rookie to this but dont you need some room to move around. from my experience it is always the amount of light and not so much the number of plants. with your low ceiling i would try to be inovative. I like the chicken wire just a little above the plants built on a level plane across the area, spread the plants as they grow threw it. another chicken wire a foot or two above the first one, push the plant down as it grows through it until all you have is a carpet of buds. Just a thought


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