need light advice! effectiveness of multiple 250w compared to one 600w?

so im dealing with a 4x4x6.5 area with 8 plants and currently have a 400wMH in the veg room, a 400wHPS and just recently added 250wHPS side by side in the flowering room.

all my experience is with 400w lights this is my first cycle using a 250 and ive never used a 600 before.
i have the opportunity to go with mutiple 250w to place around my 400w hps in the flowering room

i also have the opportunity to go with a 600w and 400 hps for the flowering room.

so i'm thinking either a 400 in the middle with a 250 on each side

or a 400 and 600 side by side rotating them every week?

i know that multiple light sources are better than one or two but ive also heard the buzz around how dense the buds become when using a 600w light.

im wondering what everyone thinks is a better option for flowering multiple plants in a 4x4x6.5 area.

im guessing there will probably be more heat overall with the 600 and i do have a bit of a problem keeping the temps down. but ive also never used a 250 so i dont know how effective a 400 with mutiple 250's would be compared to a 600 with a 400. all ballasts are digital lumatek switchable. i could also sell my 400w HPS and go with four 250w although this would take a considerablly more amount of time and effort

would anyone with more experience in different watt lights and how well they yield shed some more info on the situation? greatly appreciated!

Wow why am I the only one to not get a single reply when I need some help... hmm making me think twice about RIU
Hard to believe that no one has any experience with my question

Id appreciate it if I could get some advice because I need to make the decision today... especially since I've been giving so many replies to other peoples questions..

My flower is basically the same size as yours and I use two 400 watt HPS. A friend has been saying he has a 600 watt hps that he'll let me borrow, but I haven't gotten it yet. In my limited experience, more watts = more heat. If you can deal with the excess heat, more watts are always preferable. If you can't, though, I'd stick with what you have. I wouldn't suggest ever going down in wattage, as your results will probably be less satisfying. One big light versus more than one smaller is also concerned with space. If you have a lot of plants and a bigger area to cover, go with more lights with lower wattages. If your grow is pretty compact, I'd get as big a watt light as your cooling ability allows.

...what I can tell you, 250watt HPS produces about 29,000 lumens, 400 = 50,000 lumens, 600 = 100,000 lumens
...so, you cannot exceed 100,000 no matter how you arrange your lights. More watts = more lumens for each bulb, but...you cannot stack your lumens together, in other words....
...if you we're to put a 400 watt and a 600 watt together, you will not have 150,000 lumens, you can't exceed the 600's 100,000 lumens.
IMO, you should go with the 600, and 400.
...you might want to look into aircooling them if your having heat buildup.
...hope that helps.

trichlone fiend said:

...what I can tell you, 250watt HPS produces about 2,900 lumens, 400 = 50,000 lumens, 600 = 100,000 lumens
...so, you cannot exceed 100,000 no matter how you arrange your lights. More watts = more lumens for each bulb, but...you cannot stack your lumens together, in other words....
...if you we're to put a 400 watt and a 600 watt together, you will not have 150,000 lumens, you can't exceed the 600's 100,000 lumens.
IMO, you should go with the 600, and 400.
...you might want to look into aircooling them if your having heat buildup.
...hope that helps.

Click to expand...

Thanks guys this helped a lot! My area is 4x4x6.5 so I figured I might get more lumens per area if I had a bunch of 250s. But now I see that a 400 with a 600 is probably the best solution. I think I'm going to forget about the 250s altogether and invest in a cooltube or vented hood to dissipate some of that heat cuz once summer rolls around I know I'm going to have heat trouble. Thanks again guys for the advice id give you rep if I knew how!

If you can, try a run with both and see which ones better.

But if it were me I'd do a 400 + the 2-250.

Can't really try then both a guy I know is selling them so I'm going to either purchase one or the other... can u shed some light on why u would go with the 400 with the 2, 250s

Oh and trichlone fiend I think you might have a typo I think you meant a 250watt produces around 29,000 lumens you're missing a 0

Guess I'm going to have to go with the 2, 250s the guy sold the 600 already

FarmerNinja said:

Oh and trichlone fiend I think you might have a typo I think you meant a 250watt produces around 29,000 lumens you're missing a 0

Guess I'm going to have to go with the 2, 250s the guy sold the 600 already

Click to expand...

...yeap, yeap...I'll edit.
...you'll do great with the 250, bump it up later...try to get the light as close as possible, that's your best bet.

I started with 4 x 400watts HPS, I aircooled them and placed the light about 12 inches above the plants...I got nice nugs, but...I later put the light like 6 inches and the nugs were huge! ...it really suprised me how big of a difference it made with the difference between distances.So....I later bump'd it up to 600 because they're the most efficient (lumen/watt ratio)

yea id love to get some aircooled hoods the problem i have is that a lot of my different strains grow much differently so i have a really uneven canopy. so its hard to hit plants with the same amount of light using a 400 or a 600 (talking about 8 plants) without stacking mass amount of boxes to raise the smaller plants. i was going to get a digital 600 for cheap but it was sold already and the only other options i have are a bunch of digital 250s or an eletronic 600 and ive heard that these get pretty hot and loud. i guess im going to have to go with the 250s and try to use maybe one 250 per 2 plants? can you get the same kind of buds with concentrated 250s than with one 600? keep in mind that i can have a 400 in there surrounded by 250s an an option also.

so how about this what if i had four 250w covering a 4x4 (8 plants) area compared to a 400 and a 600 covering the same area. is it possible to get the same kind of growth with a 250 because i can place them much closer to plants and concentrate the light? and the 400 and 600 would have to be placed farther away producing less lumens per plant and giving less light to plants in the perimeter?

also heat is an issue but i would be willing to spend a lil extra on cooling if the 600 would make a huge difference in yield. of course i can on longer purchase the 600 but this would be good to know for the future. or maybe i should just scratch the 250s and just invest in another 400 and to use two 400s. hard to decide whats best for this area help!

whats the best combination in a 4x4x6.5 for these lights, keep in mind that you could only use 2-4 lights at once

which would you use and why?

three 250w
one 600w
two 400w

...imo, if your going to run any HID light in a space that small, your either going to need a kick ass vent setup, or aircool them. I've never personally grown with a 250watt, but...I have grown with the 400's as I mentioned above.

Myself, I position my bulbs horizontally, I figure my lighting by sqft. A 400 covers 3x3, 600 covers 3x4 - 4x4 , and 1000's cover 4x4 - 4x5..

...from what I've learn...the more watts you use, the further the lumens travel. The lumens deminish with distance. So...in otherwords, the more watts you use, the deeper the lumens will penetrate your garden, if you position your bulbs horizontally. I personally use 600's as I mentioned above, I position my bulbs horizontally, I keep a dense garden (sog) and the lights only penetrate about 12 inches deep into the gardens canopy....so, I lollipop anything deeper than that....that's just a technique I've convinced myself with, that will yield the most per watt with limited space.


...some people position their bulbs vertically, in my reading, vertically is the most effecient (yield per watt ratio) way to grow indoors with artificial lighting. If you browse the net, you'll see that most people growing really huge plants are positioning their bulbs vertically and hang them about 1/3 of the way into their canopy....which allows side light. I believe this is one of the most misunderstood things when talking about lights and yield. It takes many lights and alot of space to grow really big plants that yield good. If your pressed for space, you'll have to get creative. Consider your options and decide for yourself, then you'll be your own blame if your not impressed....that's easier to deal with in this game I have found....LOL

...all in all, I'd aircool my lights no matter what, HID's get hot....the digital ballest are said to make your bulbs last longer btw....also, when I switched form 400 watt magnetic ballest to 600 watt digital ballest, my electric bill hardly raised at all! ....I'd go digital without a doubt.