What is better, two 250 bulbs or single 400?

[Garm]

Ok setting up a 4x4 flood and drain table in grow tent.

What would be better coverage, a single 430 or a pair of 250's?

I realize that running a couple of Lumitek 250's is alot more $ but it really doesn't matter at this point.

Will be running air cooled hoods here.

 

[KrAzEo]

The 250 hps puts out a total of ~27,800 lumens. The 400 hps puts out ~50,000. So ~55,600 vs ~50,000. BUT you are paying for more watts with the 250s which may or may not pay for themselves come harvest - with only ~5,600 extra lumens. The 400w hps efficiency is 125 lM/w (lumens per watt), while the 250w hps efficiency is only about 111 lM/w. http://www.stonco.com/library/TechData/Wattageselectionchart.pdf

I would just go with the 400w. Actually I would just go with a 600w for a 4x4 and it is only 100w more than 2 250s and 600s are the most efficient @ up to 158 lM/w. http://www.htgsupply.com/Product-Digital-Greenhouse-600-watt-HPS-Grow-Light.asp

Hope this helps!

 

[dankerous]

actually most grow books say a few lights is better than 1 light,think of it like your like is putting out a triangle of light, 1 light would cover alot less area than 2 lights half the wattage,plus the 2 lights would distribute it more evenly, thing of it like this one light covers like this - / \ 2 smaller lights /\/\, more area covered you see?

 

[KrAzEo]

Here is a another post pertaining to a similar situation: https://www.rollitup.org/grow-room-design-setup/331052-2lx3wx8h-closet-one-400w-two.html

 

[KrAzEo]

actually most grow books say a few lights is better than 1 light,think of it like your like is putting out a triangle of light, 1 light would cover alot less area than 2 lights half the wattage,plus the 2 lights would distribute it more evenly, thing of it like this one light covers like this - / \ 2 smaller lights /\/\, more area covered you see?

That is a good point. I wonder though at what scale is it too small to be worth it in yield vs $ invested? Too lazy right now to want to think about it in numbers lol.

 

[Jogro]

"Better" in what way?

The 400 will be more cost-effective, in terms of lamp cost, bulb cost, energy cost and yield/watt energy used.

If actually used to their maximum, the 2 x 250s might give a better absolute yield. Plus having two lights gives you a lot more flexibility in terms of placement, spectrum, etc.

Note that when the plants are small and vegging you well might get away with running ONLY one 250W hps, and doing that will probably save you more in terms of energy than the increased efficiency of the 400 would!

 

[polyarcturus]

personally you would be better with 2 400w (one halide one hps). if your set on 2 250 your plants will have to be less than 2 ft tall

 

[jcommerce]

I'd personally go with the single 400. Since it's in a tent, you can line the walls with mylar and add a few supplemental CFLs in the corners. I did this and consistently pulled 6 - 8 ozs. off of 4 plants. One light, one ballast, minimal ducting with single hood, etc. Was easy to maintain 76F with the 400w.

 

[dankerous]

Im just quoting J cervantes, Im pretty sure he knows what he is on about as he has been one of the top experts in his field for some time now,

"Better" in what way?

The 400 will be more cost-effective, in terms of lamp cost, bulb cost, energy cost and yield/watt energy used.

If actually used to their maximum, the 2 x 250s might give a better absolute yield. Plus having two lights gives you a lot more flexibility in terms of placement, spectrum, etc.

Note that when the plants are small and vegging you well might get away with running ONLY one 250W hps, and doing that will probably save you more in terms of energy than the increased efficiency of the 400 would!

 

[RetiredMatthebrute]

i think the for a 4x4 tent a 600w would be your best bet. if thats not a option, i dont really have a educated opinion on the 250 vs 400 situation.

 

[nick17gar]

"Better" in what way?

The 400 will be more cost-effective, in terms of lamp cost, bulb cost, energy cost and yield/watt energy used.

If actually used to their maximum, the 2 x 250s might give a better absolute yield. Plus having two lights gives you a lot more flexibility in terms of placement, spectrum, etc.

Note that when the plants are small and vegging you well might get away with running ONLY one 250W hps, and doing that will probably save you more in terms of energy than the increased efficiency of the 400 would!

agreed! plus, if the light fails, you still have a 250w running providing light, if the 450w fails your fucked. im a big advocate of more, smaller lamps.

 

[polyarcturus]

fuck it 650w 250w MH and 400w hps full spectrum, backup lighting, cheap on the elecctric bill. i think this would be a good way to go also

 

[Garm]

Thanks all for the replys. I also have to add is that I want to use Lumitek ballasts so they could run either on 250 or 400.

 

[slider11111]

Use a 600 and get 750 grams!!!

 

[209 Cali closet grower]

430w hps I would think mybe a little better penetration to the lower buds?

 

[cannabineer]

430w hps I would think mybe a little better penetration to the lower buds?

I think 2 spaced 250s would give you better penetration than a single-source 430.

I do agree that a 4x4 is aching for six hundred watts. cn

 

[richinweed]

actually most grow books say a few lights is better than 1 light,think of it like your like is putting out a triangle of light, 1 light would cover alot less area than 2 lights half the wattage,plus the 2 lights would distribute it more evenly, thing of it like this one light covers like this - / \ 2 smaller lights /\/\, more area covered you see?

....Yep roll with that...if you get 400 watt lumitec balasts they take iether type bulb...and also take 250 watt bulbs....great versatility...jmho

 

[richinweed]

disregard the last post............zzzzzzzzzzzz

 

[209 Cali closet grower]

I think 2 spaced 250s would give you better penetration than a single-source 430.

I do agree that a 4x4 is aching for six hundred watts. cn

So you saying a 250w will give better penetration at the lower buds then a 400w?I would think 2, 250w would give better spreed of light though, but not at the lower buds?jmo

I would do the 600w too.