mh vs HPS
- Thread starter Justin510
- Start date
hearmenow
Well-Known Member
Smoke, even if you grow area is large, doesn't mean you need to fill the space with plants. Congregate your plants in a corner and place your light over there. Just put 4-6 plants there. Do what I did and stop by Michael's craft store and get some display board - they are about 4'x2' and are white. I use it as partitions in my closet.
babygro
Well-Known Member
400w MH would put out about 38,000 lumens at 1 foot onto 1 square foot. So at 2 feet it outputs 38,000/4 = 9,500, at 3 feet 38,000/9 = 4,222, at 4 feet 39,000/16 = 2,735.
So you're looking at an area of about 3-4 feet square to cover with a 400w MH for vegetative growth.
hearmenow
Well-Known Member
Smoke, of course mylar is better but what I am getting at is that you don't need to build anything new. Simply get the carboard partitions, stick your mylar on one side and presto, you have removable walls. I found that I was continually reconfirguring my space as my plants grew taller and filled out. The cardboard partitions made it super easy to increase or decrease my space in seconds. Worked for me, anyway.
BloodShotI'z
Well-Known Member
Thats encouraging....Im bagseeding it my 1st go round as well. Learning/learned alot so far. May go for some good seeds once I get these plants out the way now. My learning curve is a little steep. Probably because Im doing soil and a bubbler at the same time.....not being proficient in either. But like I said...Im learning. And everyone has to start somewhere.
babygro
Well-Known Member
Forget watts per square foot, it's a very rough guide only, and isn't accurate because every light outputs a different lumen per watt ratio.
SmokerE
Well-Known Member
That was the answer I was looking for. Finally someone else affirms this mis-information.
BloodShotI'z
Well-Known Member
Hearmenow....I was checking out your grow pics....I see your plants are pruned....I have let mine grow naturally....just wondering how much of a difference you saw in your plants after pruning.
I am reluctant to prune the fan leaves...figuring the plants need them for different reasons. Just wondering how trimming them effected your grow....for better or worse?
I am reluctant to prune the fan leaves...figuring the plants need them for different reasons. Just wondering how trimming them effected your grow....for better or worse?
nongreenthumb
Well-Known Member
How can you put any faith in that piece of crap.
If you have 140,000 lumens, and you place it a foot away, then surely the output must be 140,000, somethings wrong there. says far too low, i wouldnt take any recommendations from that, also it says you can keep a 1000w at 10 inches safely, I'd like to see someone prove that to be correct
BloodShotI'z
Well-Known Member
Gotcha...thats goes in line with what Ive read/heard. So far on the soil plants (the older 2) the 'cotyl's have yellowed and dropped off. All the rest of the leaves are still green....though I am starting to see the 1st set of fan leaves yellowing and about to drop soon. They're not getting much light.
I have 4 more in a bubbler...2 about 2.5 weeks...and the other two just a week old. Noticing the 1st two are growing really fast...and spreading out into the smaller one's light. thinking about trimming those fan leaves just so all the others get the same light...or close to it.
I have 4 more in a bubbler...2 about 2.5 weeks...and the other two just a week old. Noticing the 1st two are growing really fast...and spreading out into the smaller one's light. thinking about trimming those fan leaves just so all the others get the same light...or close to it.
videoman40
Well-Known Member
In a 3x3 area, my light outputs about 17k lumens, when placed at the proper distance.
Peace
Peace
babygro
Well-Known Member
It's very pretty isn't it, unfortunately completely useless in terms of useful useable information.
A 400w HPS outputs (that chart claims 50,000 lumens) so we'll use that. A 400w HPS outputs 50,000 lumens at 1 foot distance. A lumen is simply a measurement for how many foot candles fall on an area of 1 foot square.
So, a 400w HPS outputs 50,000 foot candles at 1 foot distance, not 15,915 foot candles that chart claims.
A foot candle is the amount of light 1 candle makes at a distance of 1 foot. So it cannot possibly output only 15,915 foot candles at 12 inches.