400 vs 600 with inverse square rule

[TEERCSIdbREEDER]

400w - 55k initial lumens vs 600w - 88k initial lumens
aircooled-reflector

now im guessing initial lumens means lumen output at the bulb. i was under the impression that a 400w created about 50k lumens at 12inches away and then being about 12.5k lumens at 2 feet away.

either way light still diminished by 75% every foot away. so if i have a 400 at 6-8 inches away, i should be pumping 4x lumens at 6in than 12 inches.

now sometimes right under the bulb ive seen some light bleeching on the leaves. i know that there is a point of no return something like 100w per square foot. so if my 400w is causing some light bleeching there is no way of putting a 600w 6-8in away and not getting bleeching.

so do i keep the 400 at 6-8in away or upgrade to a 600 and keep it 12 inches away? i cant imagine at those distances there being that big of a change in lumen output that reach the plants.

Now this is why i ask..im doing a 18g+ tupperware bucket with like 15 clones (all same strain) in dwc/aero system havent gotten that far yet. so i wouldnt need more than a 3 x 3 print bc theyll be single colas. my light is aircooled so i can place close to plant tops without burning.

Eventually after the first run and with mothers still vegging i will be adding another aircooled light with a different strain running perpetual every 30days. so do i want two 400w hps 6-8in away in a 6 x 4 x 5ft area or two 600w 12inches away?

thanks to all who contribute. the season is beginning and my minds going a mile a minute! peace all

 

[tr1ck_]

First off I'm fairly noob, but based upon what I have read and heard I would go with the 600's if you can control the heat. With a 6x4 setup you have 24 square feet. So with (2) 600's that would put you at 50w per sq ft which is what a lot of people recommend. The (2) 400's would put you at 33w. The 600's should also penetrate a bit deeper and hopefully product quality nug further down the plant.

 

[TEERCSIdbREEDER]

wouldnt it be 400w covering 9 square ft? 3 x 3 under each light, horizontal light.

like i said ill be using something like a 18g bucket (about 2ft x 2ft).

 

[tr1ck_]

Well if you have a 6x4 area, why not use all of the space when you have 2 lights, You could just have them cover a 3x4 area each instead of a 3x3 area. Throw in a screen and you could have a completely even canopy

 

[TEERCSIdbREEDER]

im used to growing organically in 3 gallon buckets, with long veg times. weight really isnt an issue as ive gotten 8oz off of 220w and close to a p off of my 400w now.

some old photos..

want to simplify things and get a little more scientific with hydro. im just wondering if by 'upgrading' am i really upgrading..200-400w extra in electricity should equal 150-300g im guessing and i really dont see those extra results with the way i plan on growin in the near future.

 

[tr1ck_]

If you were able to keep an even canopy so that you could get even light distribution from about 10-14 inches with the (2) 600w covering the entire 6x4 area, you would definitely get a lot more weight than with (2) 400's in my opinion.

Although a pound off of a 400w is very impressive so trust your instincts. I hope I can pull a pound of my 400w

 

[TEERCSIdbREEDER]

only problem is i would need at least another 30 plants to fill that void. wayy to much for me. i just want to clone>root>1wk veg>flower.
so 15 plants a piece x2 lights. i would be taking 25+ clones every two weeks or so. thats already going to keep me quite busy plus the outdoor season.
i just want to kno with my set-up...2 18g containers with 15 or so clones in each (single colas) would an extra 200w at double the distance away lead to 150+ grams each light. if not its not really worth it.

i agree even canopy is the way to go. last couple of runs ive been looking for a certain plant so ive been running different seeds, sativas and indicas alike.

this was a 220w t5 grow for the hell of it. almost 8oz dry.

 

[tr1ck_]

You don't think you could take those 30 plants, and veg them for like 10 days instead of 7 and get them to fill in that extra 3sq ft per light?

 

[nut]

600 watt 95,000 lumens, 400 watt 55,000 lumens almost 2x the lumens for 200 watts more if that does not sell you then nothing will.

600s beat 400s hands down stick them in air cooled hoods and get them closer than the 400s

 

[TEERCSIdbREEDER]

600 watt 95,000 lumens, 400 watt 55,000 lumens almost 2x the lumens for 200 watts more if that does not sell you then nothing will.

600s beat 400s hands down stick them in air cooled hoods and get them closer than the 400s

hortilux hps: 600 is rated at 88k and 400 is 55k.

i agree that 600 is 200 more watts than a 400 but if it doesnt equal at least 150 extra grams it isnt worth it right? would u go thru the process of purchasing one mayb two lights-$350-700 and i get no noticeable difference in weight or quality than it clearly isnt worth it.

i havent tried but i have gotten some bleeching with the 400 so a 600 at the same distance seems impossible? so then i would raise to 10-12inches and lose at least 40% total lumens due to the extra 6-8inches away.

so just for arguments sake lets say at 12in the 600 produces 88k lumens and the 400 produces 55k. so at twice the distance its 1/4 the lumens, so why wouldnt 6 inches away be something like twice the lumens if 12 less than a foot (the bulb) should be 4x the lumens that are measured at 12in.

again so twice the intensity at 6 in would be 110k lumens with the 400w and 176k lumes with the 600. the 600 does surpass but cant be placed so close, whether its heat, radiant energy, or light bleeching.

so again 400 at 6inches or 600 at 12inches. the inverse light rule would state that the 400 would be more effiecent.

i could be wayyyy off but this makes sence to me even tho its hard to put in words. i guess if i bought the 600 and a light meter i could easily get a concrete answer but we dont all that kinda money to throw around.

mayb someone out there with some spare time can meter the difference im sure others have thought the same thing.

 

[redbudduckfoot]

i can get a pound off my 600 w/ my eyes closed. its a struggle for me to get more than 10z's from my 400. completely stopped using the 400 and am now going w/ two sixes.

there is no question that the 600w light is the most efficient hps available, lumen per watts.

 

[Hammerhead]

I love my 600 there is no compaison the 6 will outperform the 4 all day any day. I say at 600 @ 8" and call it good

 

[nut]

hortilux hps: 600 is rated at 88k and 400 is 55k.

i agree that 600 is 200 more watts than a 400 but if it doesnt equal at least 150 extra grams it isnt worth it right? would u go thru the process of purchasing one mayb two lights-$350-700 and i get no noticeable difference in weight or quality than it clearly isnt worth it.

i havent tried but i have gotten some bleeching with the 400 so a 600 at the same distance seems impossible? so then i would raise to 10-12inches and lose at least 40% total lumens due to the extra 6-8inches away.

so just for arguments sake lets say at 12in the 600 produces 88k lumens and the 400 produces 55k. so at twice the distance its 1/4 the lumens, so why wouldnt 6 inches away be something like twice the lumens if 12 less than a foot (the bulb) should be 4x the lumens that are measured at 12in.

again so twice the intensity at 6 in would be 110k lumens with the 400w and 176k lumes with the 600. the 600 does surpass but cant be placed so close, whether its heat, radiant energy, or light bleeching.

so again 400 at 6inches or 600 at 12inches. the inverse light rule would state that the 400 would be more effiecent.

i could be wayyyy off but this makes sence to me even tho its hard to put in words. i guess if i bought the 600 and a light meter i could easily get a concrete answer but we dont all that kinda money to throw around.

mayb someone out there with some spare time can meter the difference im sure others have thought the same thing.

If you cant beat a 400s using a 600 then somthings wrong somewhare? watt for watt the 600 will beat the 400 gram for gram.

The light is not whats bleaching you plants it the heat if you can cool the light enough you can get the plant to grow into the aircoold hoods glass. The sun puts out far more light (100,000 lumens) than a 400w or a 600w HPS why then do sun loving plants such as ganja not burn in the sun? its not the light its the heat from the bulbs that bleach the plants.

the 600w a foot above the plants will give a better more even spread of light the same as the 400w but over a wider area = more yield PSF (per square foot) not just 1sqf under the bulb like your comparing it against.

p.s
the sunmaster 600w son T+ gives 95,000 lumens from a new bulb. initial lumens = the first 100 hours of a bulbs usage

 

[nut]

lets look at the rule of thumb of 50 watts per square foot.

a 400w @ 50 watts psf = 8sqf
a 600w @ 50 watts psf = 12sqf

lets look at the lumens each bulb puts down on avarage over the areas 8 and 12 psf of garden at 50 watts.

the 400w garden puts down 55,000 lumens over an area 8sqf- 55,000/8 = 6875 lumens.
the 600w garden puts down 95,000 lumens over an area 12sqf- 95,000/12 = 7916 lumens.

as you can see the 600 puts down more lumens over a lager area. e.g lets say an avrage garden yields 1 oz per square foot ( not to hard to accomplish)

The 400w garden will give you 8oz
The 600w garden will give you 12oz

the 600w is also putting down 1041 more lumens psf = a better chance of hitting the avarage 1 oz psf than the 400w.

saying that its down to the grower and not what it says on paper, a good grower will always get more e.g a gram per watt

 

[TEERCSIdbREEDER]

i guess im seeing it differently...ill go with a 600 and see what my results are. thanks for all who chimmed in.

600w illuminating a 2 x 2ft 18g tupperware bucket with single (no veg) plants (x20). seems like alot of wasted light.

i totally agree if i wanted to run plants from corner to corner the 600 would surpass the 4 no doubt. i have a 5ft roof so if the bucket is like 2 ft tall and the plants are another foot tall and the reflector is another 12ins or so ill have 10inchs from tops to glass of reflector.

the first pic i posted you can see the plant in the center much yellow. i agree it could have been heat but i run a stanley cage fan at the top of the tent about 3 ft to the reflector and then to my scrubber. the cage fan is set on high so if that cant cool it then im screwed for the 600.

i kno watt for watt more is more but i figured with the extra distance i can get with the 400 i could maximize on my 18g bucket. like i said before i got over 7oz with a 4ft t5 unit only 220w something like .9gpw and it only had 20k lumens but it was scrogged and tops were 2inches away from light. without the inverse square rule i dont see almost 1gpw with a 5wk veg.

again thanks all hopefully will b creating a diary in the next month or so, lots of great genetics to play with.

better start looking for some 600w completes. peace all!

 

[nut]

i guess im seeing it differently...ill go with a 600 and see what my results are. thanks for all who chimmed in.

600w illuminating a 2 x 2ft 18g tupperware bucket with single (no veg) plants (x20). seems like alot of wasted light.

i totally agree if i wanted to run plants from corner to corner the 600 would surpass the 4 no doubt. i have a 5ft roof so if the bucket is like 2 ft tall and the plants are another foot tall and the reflector is another 12ins or so ill have 10inchs from tops to glass of reflector.

the first pic i posted you can see the plant in the center much yellow. i agree it could have been heat but i run a stanley cage fan at the top of the tent about 3 ft to the reflector and then to my scrubber. the cage fan is set on high so if that cant cool it then im screwed for the 600.

i kno watt for watt more is more but i figured with the extra distance i can get with the 400 i could maximize on my 18g bucket. like i said before i got over 7oz with a 4ft t5 unit only 220w something like .9gpw and it only had 20k lumens but it was scrogged and tops were 2inches away from light. without the inverse square rule i dont see almost 1gpw with a 5wk veg.

again thanks all hopefully will b creating a diary in the next month or so, lots of great genetics to play with.

better start looking for some 600w completes. peace all!

sounds like your doing ok with what you got. If i was you i would get if you want to upgrade? a 600w dimmable digital ballast that way you can run the 400w in the summer time and in the winter flick it to 600w you have the best of both worlds with just one ballast.

 

[el dub]

I've run 2x3's with a 400 and 2x4" with a 600 with good results.

If you are adamant about only wanting to press 4 sq ft with a light, 400 watts is plenty, imo.

lw

 

[guestaweed]

im used to growing organically in 3 gallon buckets, with long veg times.

How LONG do you veg them?
I know it doesn ' t help your question
but it would help my current grow..which would like itself to be quite similar
also under 400w lamp..