How many plants can I put under a 400 watt HPS?

put the plants in a circle around the light, hang the light vertical about 2 feet off the ground. Vertical grow is the future. I have a four by four circle with a 400 watter in the middle. I have 15 plants on the outside of the circle on blocks about a foot of the ground. The other 15 plants I have inside those plants on the ground. I get a huge circle of weed. The ouside plants climb up the wall, while the ones on the floor get to about the middle of the other plants heightwise. The light hits all the plants, I get nugs from the dirt in the pots to the top of the plants. Vertical growing is the future.

about 20 under a 400 watter if used right...

https://www.rollitup.org/general-marijuana-growing/70310-vertical-grow-400-watt-hps.html

yeah.. 14 inch minimum, learned that the hard way my first grow

ran outta room when they flowered and the taller colas just dissentigrated at 10-8 inches

wow.. Up to 20 plants/1HPS 1000w! shure iff yaa wanna some pfatt buds!

I've got 9 un-sexed plants under my 430w HPS, with COOL Junior Hood.. Hopin to have atleast 5 by the end Also got some CFLs mounted on the walls for my babies' undercarriage

I am a fan of using more smaller lights then one big light, you can spread your light around more. I use 3 150w hps bulbs in my closet and I grow 14 plants. When you use the smaller hps bulbs you can put then closer to your plants then 14 inch. I think that is too far away and causes stretching. I keep my 150 watters about 6 inches away with no harm to my plants, you just have to keep an eye on them. Any closer then 3-4 inch and you will start burning. I also stick a few ntural light bulbs in along the side of my plants. Hope this helps.

piro20 said:

I am a fan of using more smaller lights then one big light, you can spread your light around more. I use 3 150w hps bulbs in my closet and I grow 14 plants. When you use the smaller hps bulbs you can put then closer to your plants then 14 inch. I think that is too far away and causes stretching. I keep my 150 watters about 6 inches away with no harm to my plants, you just have to keep an eye on them. Any closer then 3-4 inch and you will start burning. I also stick a few ntural light bulbs in along the side of my plants. Hope this helps.

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As far as lumen per watt output, 600 watt is the most efficient lighting.

got 6 oz off my last WW grow 6 females...400w HPS 4x4 space with cooltube, walls lined with mylar 3gal grow bags, FF Ocean Forest soil, tiger bloom and a touch of 20-20-20 MG all purpose(yeah I grow somewhat inorganicly)...there are spots under the cooltube where I was placing colas 2 inches away from the light...it all depends on feel. New grow, new location still same specs but starting with 17 unsexed...hoping for roughly 10-12 females...lst works fine...I guess SOG is the real name...you do not get gigantic buds but you get nice 7-10 gram after curing colas and the smaller tops are anywhere from 2-7 grams each with around 10-14 per plant as long as you do not pick at them early
I think the real key is not to overfertilize and even though it may be back breaking...you need to move those girls around a bit...even a small bit of light hitting an area will produce a bud site.Small buds still smoke

https://www.rollitup.org/general-marijuana-growing/70310-vertical-grow-400-watt-hps.html just go here and look at his setup

as many as you can get in 8sq feet. that way you have 50 watts per square foot, which is optimal

kearners said:

u can get a 250watt hps right?

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I have set up 12 plants. two cirlcles of 6 with tube light in middle and 400w over each circle. Hoping that will work well as they will b close together.

I have 5 Grape Krush in a 4x4x6 with a 400watt MH and at 3 corners mid plant level I have (6) 100watt equivalent 6500k cfls. Two of my plants are at 25 inches and the other 3 are at 20-22 inches. I already can see how only 3 plants will have enough room to be flowered in so I am buying another tent and light set up. I Had a grow previously and learned to be more patient and let my ladies veg big so I can yield well. It sucked vegging and flowering two beautiful plants and only getting .75 oz per plant. I am going to veg these girls until 36 inches each and hopefully have three to harvest from each tent at over 4-5 feet of big kind bud. GO BIG OR GO HOME!

jEthereal said:

It all depends on how TALL the plants are when you switch to 12/12.

You could EASILY do 16 plants under a 400w HPS. How so, you ask?

FLOWER AT 6"!!

If it is done right then you'll be able to have a bunch of mini-cola plants.

16 plants x 1/2oz expected yield =

One question - What's the 'footprint' of your tubs? ie - How much space (LxW) do your tubs take up when you have them arranged how you want? 4x4? 5x5? etc....

Your spatial 'footprint' when growing with a 400w HPS should be around 4x4. It's YOUR choice on how to accommodate your plants into that space.

There isn't really a 'set' number of plants that are appropriate with a certain wattage.

So to say 4-6 plants WITHOUT offering the SIZE of said plants is a very inaccurate statement when trying to help a newbie.

jE

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I agree 100% !

I is about the size of the area you cover. I have all my new plants growing in bag now as opposed to pots. They take up less area so I can get more plants under my HPS. It is all about how you use the space. I can have 15 smaller plants or up to 8 big ones in my space. It just depends on how much space they take up.

There is definately no set amount of plants under a light. It all just depends on space and how relfective your room is, etc etc

When I was doing 400w, I tried to have 6 Indicas under it in a 3x3 tray. I found that to be too cluttered and I get better yield from flowering smaller and bending, or less tree-like plants.

I went to 600 in my 3x3 and I'm doing 6-7 very well now.

You should be able to get the tops within 6" of the 400w glass if your venting your light correctly. Only issue is you can't use the footprint of the hood very well. The light doesn't come out of it straight horizontally, a plant the same height just off the the side of the hood will not get light to the top of the plant. Light will start hitting a few nodes down and that why the light should be a little higher, to use the full footprint

ND