1000 watt hps penetration question

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rkymtnman
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1000 watt hps penetration question

Post by rkymtnman »

according to one of the more popular charts about lights, a 1000 watt hps is effective from 10 inches to 36 inches away from the plant. closer than 10" is too much light: more than 36" is too low light.

if this is correct, a 4 ft tall plant would be too tall for a 1000 watt? so then how do you do a tree grow with one light?
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Re: 1000 watt hps penetration question

Post by Happyweedz »

Pass....
"Fill it, Light it, Shut-up & Close the door!"
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Re: 1000 watt hps penetration question

Post by GrowTutor »

It's not entirely correct and it depends on what you call effective. With a single 1KW light I wouldn't want to go over 4-5' tall. I wouldn't want to go over 2'-3' tall even with the best LED lights.

Remember, not all of the vertical grow area is used/measured. You lose about 1' or more from your pots/hydro unit and you'll lose another 2' from the top to hang the light and give it some space. That's 3' off already, if you have 8' ceilings that only leaves 5. Additionally 36" might be fine for clones or newly vegging plants. Under 10" might be OK if you water cool your lights and/or add CO2. Even with a 1000w light you'll not get top-shelf results all the way down the plant to the pot but you will get them deeper than LED. So, a 4-5' tall plant can still be considered to be a tree. Now do you see why LED plants need to be so much shorter?
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Re: 1000 watt hps penetration question

Post by rkymtnman »

yep, gotcha. i was in my room just taking some measurements almost exactly like you are talking about. how tall the tubs will be off the floor and then how far from the ceiling the cooled hood would be.

i think if i grow a 4 footer, the 1000 will give just about the right amount of penetration. i just was worried about growing something too tall and still having too much fluff bud at the bottom of the plant

but yeah, i wish i had a higher plant count. i think if i had more shorter plants, i would be able to use the 400 for full cycle. but like you've said before, each individual has to dial in their enviro to get the best quality and quantity.

when you did trees, how tall were they? and about how much did you yield roughly per plant?

thanks,RKY
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Re: 1000 watt hps penetration question

Post by GrowTutor »

I know for a fact that the 1kw light will grow 4' tall plants and while the quality will diminish from top to bottom (it just has to), you'll still end up with a lot MORE top-shelf flowers than you would with lesser lights. If you ScrOG then they really won't get that tall due to training so 1kw would penetrate very well. If you're really worried, keep them shorter (this time) and adjust taller (or add a screen/lst) if you have too much open canopy. Remember to allow room for the extra horizontal growth too, you don't want them overcrowded either.

It's not too late to change your plant count. What are your dimensions for this again? Did you plan this all out based on an end goal, space/other limitations? Why are you building it the way that you are? (Maybe we should start design topic in the Indoor Grow Room Plans & Setup forum for that) ;)

I have 8' ceilings so I was limited to 4-5 feet and I averaged about .8g/w growing 1-2 plants per light with selective pruning/toping/fimming in *DWC. I could have gotten more if I had changed genetics but I was happy with what I had and it didn't require a lot of plants to keep going. Now that I'm starting from scratch and the laws appear to be changing faster I plan on rolling the dice and changing things up. I'm still deciding what I want to do next, long term, but I think I'll get several small tents to experiment. I'll need them to test stuff for my product reviews later anyway. ;)
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Re: 1000 watt hps penetration question

Post by rkymtnman »

unfortunately, CO chooses my plant count. i have 6 max. but i know i can get what i need from 4. my area is done too. it's 4x3x8.

with my tub height and ceiling max, i should fit a 4 footer no problem. can't get too much above that though.

my goal is to have enough where i don't have to worry about it until the next one. i'd like to do 3 pulls a year. maybe 4. so 4 plants times .6 to .8g/w x 1000 watt x 3 or 4 times a year= goal.
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Re: 1000 watt hps penetration question

Post by SisterMaryElephant »

You might fit a 4 footer but can you fit 4 of them? ;)

.7g/w x 1kw = 700g = ~24oz x 4xYear = 96oz = 6lb/yr or .5lb/month or 2oz/week ;)
I also run a medical grow consulting business in SoCal.
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Re: 1000 watt hps penetration question

Post by rkymtnman »

2 zips a week, huh? i guess i better start getting my tolerance up. i do plan on doing edibles and maybe some extracts too. so the more the better. it's like bacon, you can never have too much.

i had 4 2.5 footers last go round in only one tote in the same room. so i figure the same number spread out into 2 totes would be better. i'm gonna shoot for somewhere between 3 and 4 foot at finish. might have to do a bit of pruning and spreading them out into a screen.
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Re: 1000 watt hps penetration question

Post by SisterMaryElephant »

Damn, now I want bacon. ;)
I also run a medical grow consulting business in SoCal.
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Re: 1000 watt hps penetration question

Post by hemivette »

Ive grown lots of Sativas in a small space. You cant be afraid to SuperCrop. Or you can use Bendz, if you are. Dont be afraid to take the tops, and let the bottoms go a couple more weeks. Peace. h
Last edited by hemivette on Thu Dec 26, 2013 5:23 pm, edited 1 time in total.
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