150w x2 HPS vs 250w x1

Does two 150w hps panels add up to be a 300 w panel?

Trying to maximize my yeild scrog space of 2x2 feet.

I have read people in this forum use additional CFLs.

Appreciate any insight, thanks in advanced.

You will not get 2 150 watt HPS's in a 2x2. There is just not enough room.

If you could somehow fit 2 150w hps in that space, that would give you the best coverage, thus maximizing yield. Just make sure you can control the heat in this tiny grow box.. check out cree cob led lights. Might be a better option for a smaller grow.
http://timbergrowlights.com/products/

rickymac21 said:

If you could somehow fit 2 150w hps in that space, that would give you the best coverage, thus maximizing yield. Just make sure you can control the heat in this tiny grow box.. check out cree cob led lights. Might be a better option for a smaller grow.
http://timbergrowlights.com/products/

Click to expand...

Two will fit, side by side.

I have a carbon scrubber and a 123cfm exhaust fan.

The 150w stays very cool in there. I'm just wondering if i would really get more yeild by having an extra one.

Or just eventually replace it with a 400w.

My tent is 2x2x5'3.


I curious to understand if more light will actually make bigger buds. Or if it will just be a slight difference. Let's say I pack the 2x2 space really well with proper scrog and low stress training right off the bat.

There must be some ratio where in a 2x2 spot your crop won't benefit from more light.

in a space that small a single150 watt should work fine.a single 250 watt might be overkill but if you get a single light high enough you should get pretty uniform coverage from a single light.cooling a grow room that small might be a bigger concern

igronao said:

Two will fit, side by side.

I have a carbon scrubber and a 123cfm exhaust fan.

The 150w stays very cool in there. I'm just wondering if i would really get more yeild by having an extra one.

Or just eventually replace it with a 400w.

My tent is 2x2x5'3.


I curious to understand if more light will actually make bigger buds. Or if it will just be a slight difference. Let's say I pack the 2x2 space really well with proper scrog and low stress training right off the bat.

There must be some ratio where in a 2x2 spot your crop won't benefit from more light.

Click to expand...

with hps in a space that size multiply lumen output by 0.0332 to get par umoles (horizontal scale) the graph will show plant activity. this will help you find the point of diminishing returns. for me 500-600 umoles work very well but I grow with T5s

igronao said:

Two will fit, side by side.

I have a carbon scrubber and a 123cfm exhaust fan.

The 150w stays very cool in there. I'm just wondering if i would really get more yeild by having an extra one.

Or just eventually replace it with a 400w.

My tent is 2x2x5'3.


I curious to understand if more light will actually make bigger buds. Or if it will just be a slight difference. Let's say I pack the 2x2 space really well with proper scrog and low stress training right off the bat.

There must be some ratio where in a 2x2 spot your crop won't benefit from more light.

Click to expand...

A 400w would be overkill. And I'm not sure if there is a formula, but I know there is a BASIC rule of thumb of 50w per sq ft. That's a pretty vague statement and doesn't mean a whole bunch on its own, buthe basically anything over than and the return isn't worth the cost.
With 2x2 and 300w you have roughly 75w per sq ft. But again that's vague. Really you would want a PAR reader instrument to physically see the benefits of 2 light coverage vs 1.
With your space, I would recommend this......
http://timbergrowlights.com/200-watt-cree-cxb3590-4-cob-kit-meanwell-hlg-power-supply-free-shipping

With that setup, you can get optimum coverage with one cob placed evenly in each square ft.
Plus it'll run cooler than the hps bulbs.



Now how much more will increasing from 150w to 200-300? Who knows. The fact is, you can achieve better coverage and canopy penetration with multiple light sources, which will increase yield. As long as you don't go over kill to where you have diminishing returns. If adoing another 150w cost you $10 more a month to run, but you increase yield by 14g-28g, then it was a good investment and justified in my opinion.

I had 400W HPS hood x 240W LED x 300W LED x 2 50W UFO LEDS in a 3x3x5.6....
Anything can be done if ya want too.
Got about 2 LBs out of that one... Open it was a jungle. Colas all up past the hood in the top. Was getting ugly in there really.

mauricem00 said:

with hps in a space that size multiply lumen output by 0.0332 to get par umoles (horizontal scale) the graph will show plant activity. this will help you find the point of diminishing returns. for me 500-600 umoles work very well but I grow with T5s

Click to expand...

Nice graph! Thanks for sharing that.

rickymac21 said:

A 400w would be overkill. And I'm not sure if there is a formula, but I know there is a BASIC rule of thumb of 50w per sq ft. That's a pretty vague statement and doesn't mean a whole bunch on its own, buthe basically anything over than and the return isn't worth the cost.
With 2x2 and 300w you have roughly 75w per sq ft. But again that's vague. Really you would want a PAR reader instrument to physically see the benefits of 2 light coverage vs 1.
With your space, I would recommend this......
http://timbergrowlights.com/200-watt-cree-cxb3590-4-cob-kit-meanwell-hlg-power-supply-free-shipping

With that setup, you can get optimum coverage with one cob placed evenly in each square ft.
Plus it'll run cooler than the hps bulbs.



Now how much more will increasing from 150w to 200-300? Who knows. The fact is, you can achieve better coverage and canopy penetration with multiple light sources, which will increase yield. As long as you don't go over kill to where you have diminishing returns. If adoing another 150w cost you $10 more a month to run, but you increase yield by 14g-28g, then it was a good investment and justified in my opinion.

Click to expand...

I may make my own cob kit. Thanks for the info on that. The price is quite steep.

1) Need a digitizer
2) COB led.

One digitizer depending on watts I will only need 1, and then have the cobs attached.

Meanwhile, I am going to try the 150 w hPS that I have and see if any of the corners is lacking light. If so, I may quickly add hanging CFLs on the dark spots.

mauricem00 said:

in a space that small a single150 watt should work fine.a single 250 watt might be overkill but if you get a single light high enough you should get pretty uniform coverage from a single light.cooling a grow room that small might be a bigger concern

Click to expand...

Thanks for the info.

igronao said:

I may make my own cob kit. Thanks for the info on that. The price is quite steep.

1) Need a digitizer
2) COB led.

One digitizer depending on watts I will only need 1, and then have the cobs attached.

Meanwhile, I am going to try the 150 w hPS that I have and see if any of the corners is lacking light. If so, I may quickly add hanging CFLs on the dark spots.

Click to expand...

have you considered using smaller leds spread out to get more uniform coverage? these will give you 144 lumens per watt at 1'35 amps and 172 lumens per watt at 600ma with no hot spots http://www.digikey.com/product-detail/en/samsung-semiconductor-inc/SI-B8T342560WW/1510-1324-ND/5875178 a constant current led driver would be the best way to power them

mauricem00 said:

have you considered using smaller leds spread out to get more uniform coverage? these will give you 144 lumens per watt at 1'35 amps and 172 lumens per watt at 600ma with no hot spots http://www.digikey.com/product-detail/en/samsung-semiconductor-inc/SI-B8T342560WW/1510-1324-ND/5875178 a constant current led driver would be the best way to power them

Click to expand...

So that strip is approximately 38 w at 24 v.

I could have 4 of those strips on the outer sides of the box.

The digitizer for that is cheep. The strips are around 20$ each. That's like 100$ for the full project materials. For an additional 150 or so Watts.

That's not that bad. And it's true watts not like the cheep knockoffs we find selling 200w panels that draw only 80w.

igronao said:

So that strip is approximately 38 w at 24 v.

I could have 4 of those strips on the outer sides of the box.

The digitizer for that is cheep. The strips are around 20$ each. That's like 100$ for the full project materials. For an additional 150 or so Watts.

That's not that bad. And it's true watts not like the cheep knockoffs we find selling 200w panels that draw only 80w.

Click to expand...

you could run all 4 in series and run them off one meanwell drive.your are smart staying away from cheap chinese diodes. some of them are less effiecient than CFLs. a driver like this may work well for you http://www.jameco.com/z/HLG-185H-C1400B-Mean-Well-200W-Single-Output-LED-Power-Supply_2189345.html they are adjustable from 700 to 1400ma. those strips do not have current limiters so you need to use a constant current driver. just like on a COB. 4 of those strips would give you 19200 lumen. much more light and less heat than a 150 watt HPS

mauricem00 said:

you could run all 4 in series and run them off one meanwell drive.your are smart staying away from cheap chinese diodes. some of them are less effiecient than CFLs. a driver like this may work well for you http://www.jameco.com/z/HLG-185H-C1400B-Mean-Well-200W-Single-Output-LED-Power-Supply_2189345.html they are adjustable from 700 to 1400ma. those strips do not have current limiters so you need to use a constant current driver. just like on a COB. 4 of those strips would give you 19200 lumen. much more light and less heat than a 150 watt HPS

Click to expand...

That's perfect!

So maybe 120$ or so for a great led light. I've seen drivers at 30$ which can help cost.

igronao said:

That's perfect!

So maybe 120$ or so for a great led light. I've seen drivers at 30$ which can help cost.

Click to expand...

yes and it would replace the hps light with a lot less heat. you will need to mount them on a metal sheet to cool them. and you could suppliment with CFLS or T5s to get more light

mauricem00 said:

yes and it would replace the hps light with a lot less heat. you will need to mount them on a metal sheet to cool them. and you could suppliment with CFLS or T5s to get more light

Click to expand...

Thx for all the info.