How many plants can I put under a black star 240 watt?

I love the informative post..

I would say 2 to 3 big plants under that light. Many more if you scrog. I would use my 21 plant tote under that light, I would probably pull a little under a 1/2 oz a plant, but still a good yield. Considering how many plants you start with.

Ive been growing hps for years, do love the proven technology. But once you start using over 4+ hps in one room you need some serious cooling. I was using my air condition, in line fan, humidifier, with bulbs in the air cooled glass tubes, heat was my main issue. Living in the desert, where it gets 100+ its hard to control. Helicopters will easily do a fly by, and see that one room in your house with burning walls. Thats the reason I went to LED.

puffenuff said:

What's up Jorgo? I also have an oblong shaped 2x3 space. If you're looking to get something with the about the same output of a 250w hps which I think is a good fit for that size space, I recommend 180w or 200w from advanced. More if you want to blow it up. I've grown with both a 180 and 200 in a 2x3 and get great results. If you can fit more power in there and are comfortable with cost of buying another led, then I'd shoot for more like 350-400w in there and you'll be sitting very nice.

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My question is how did your grows with 180 and 200 watt LED panels compare to a 250W HPS? Ever done that sort of comparison?

Also, relevant to the question, were those the nominal power draws for the panels, or the actual draws?

For example, the $300 Blackstar 240 actually draws about 133W. The $300 Hydrohut Pro-grow 180 supposedly draws 160W. Advanced LED claims an actual draw of 180W for its $540 180 panel. (I just looked at their website and didn't see a 200W model).

Advanced isn't making direct comparisons with HPS but claim a generic 50-70% energy advantage. In other words, they're implying (but not outright saying) that their 180 is as good as a 400W HPS. Hydrohut claims (or used to claim) the following explicitly, which is lifted right from a Google cache of their website:

Our Pro-Grow 180 excels over a traditional 400 watt HID system.

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I find it hard to believe that this 160 watt system outperforms a 400W HPS or even comes close.

Still, if either of the $300 panels were even close in performance to a 250W HPS, I'd be all over them.

In contrast, if I have to buy two of these LED panels at about $300 each (let alone two at $550 each) to achieve the performance of one $150 250W HPS, I really don't see the point of the LEDs.

Which is it?

Jogro said:

Just because this is the LED forum, I'm not allowed to mention HPS lamps, even if they may be a better choice for a given application?
Because this is the LED forum, nobody is allowed to draw comparisons between HPS and LED lighting? Isn't that sort of the point of an LED forum?

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yes. lol

I'm not believing anything. You may have noticed I said "*IF* LEDs are twice as efficient as HPS".
The claim has been made, but I certainly don't know it to be true, which is why I brought up a 250W HPS instead.

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Agreed. I don't think LED's are twice as efficient, but they are certainly more efficient.

Well, I thought the whole point of LEDs is that you can get away with LESS power than HPS.

If I really have to put in a full 300-400 watts of LED to light up a 2x3' space, why shouldn't I just go with HPS lighting?

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lol, you don't have to, but having 300watts of LED jammed in that small of a place is more like 400+watts of HID with none of the heat set backs... I say use almost equal wattage to HID for similar applications, and get better results with lower cooling costs, IR signatures, etc.

I can pick up two 150W HPS lamps for well under $200 together and I *know* those will give excellent results in that space.

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Alas, tis' the same with any new technology....

I don't even think I can get one good 200W LED panel for that price.

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Alas, tis' the same with any new technology.... lol

If I have to run the LEDs with the same actual power draw as HPS then there is no savings in electricity and little savings in heat to boot.

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Agreed, that's why you can run about 60-70% as much wattage with similar results. It's the same reason watts/sq ft doesn't work as an accurate measure. Also the watts/lumen output of LED's is much higher, so less wattage is required to make the same amount of light, also negating the usage of watts/sq ft.

I disagree.

First of all, HPS is still the gold standard for lighting in indoor growing, which is why virtually every commercial grower uses it. 50W/sq-foot isn't an absolute law, its basically a first estimate to optimize coverage.

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...for HID lighting.

Ultimately, no matter what type of lighting you use, be it HPS, linear fluorescent, CFL, plasma, LED, induction lighting, its still appropriate to relate light output to energy consumption. How else are you going to compare setups or decide what size lamp to use for your space? The way to do that is with watts/unit area.

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nope, see above... watts/sq ft will tell you how efficient the lights are. If you need 50 watts/sq ft HID = 37 watts/sq ft LED, you know which light is more efficient.

My question was, what's the optimum setup for a 2x3 space.
If I really need to use 300-400 watts of LED, its not clear to me why I should choose LEDs.

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You don't, but it'd be like running 600watts of HID in a 2x3 space... overkill Hell, I'd run 1200 watts of LED in a 2x3 space if I could. lol

I must admit as a mod for the led section you do seem a little biased towards hps whyte'..
Anyways check here.. http://gudomeledgrow.com/blog/?page_id=31 these lights claim, with pretty well documented grows at least 1.7 gram/watt and some even more.. but look at the prices 200 euro's+ for 70/90 watts of power..
Led's do easily beat out hps for scrog type grows (or even normal grows with well chosen vertical light placement) watt for watt but the expense is still huge..
If you want to experiment look here.. http://buymarijuanaseeds.com/community/threads/how-to-build-your-diy-led-array.117772/ towards the end of the thread with the more recent led diodes the results are phenomenal.. 20 watts for over an ounce in one pc grow..

Loper said:

I must admit as a mod for the led section you do seem a little biased towards hps whyte'..
Anyways check here.. http://gudomeledgrow.com/blog/?page_id=31 these lights claim, with pretty well documented grows at least 1.7 gram/watt and some even more.. but look at the prices 200 euro's+ for 70/90 watts of power..
Led's do easily beat out hps for scrog type grows (or even normal grows with well chosen vertical light placement) watt for watt but the expense is still huge..
If you want to experiment look here.. http://buymarijuanaseeds.com/community/threads/how-to-build-your-diy-led-array.117772/ towards the end of the thread with the more recent led diodes the results are phenomenal.. 20 watts for over an ounce in one pc grow..

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Lol. Everyone has thier own opinion .. Until I start seeing price drop then I'll consider but I'm entitled to my opinion ain't I? If you feel it fits your needs go for it.. I say what I would do I didn't say what you should do!!!

I would do one plant scog or two start flowering at 1.3 feet tall

Jogro said:

My question is how did your grows with 180 and 200 watt LED panels compare to a 250W HPS? Ever done that sort of comparison?

Also, relevant to the question, were those the nominal power draws for the panels, or the actual draws?

For example, the $300 Blackstar 240 actually draws about 133W. The $300 Hydrohut Pro-grow 180 supposedly draws 160W. Advanced LED claims an actual draw of 180W for its $540 180 panel. (I just looked at their website and didn't see a 200W model).

Advanced isn't making direct comparisons with HPS but claim a generic 50-70% energy advantage. In other words, they're implying (but not outright saying) that their 180 is as good as a 400W HPS. Hydrohut claims (or used to claim) the following explicitly, which is lifted right from a Google cache of their website:


I find it hard to believe that this 160 watt system outperforms a 400W HPS or even comes close.

Still, if either of the $300 panels were even close in performance to a 250W HPS, I'd be all over them.

In contrast, if I have to buy two of these LED panels at about $300 each (let alone two at $550 each) to achieve the performance of one $150 250W HPS, I really don't see the point of the LEDs.

Which is it?

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Although I've never grown with a 250w or 400w hps only a 600w, I can say I think my 180w and it's actually a 200w diamond series (should have mentioned that previously, that's why you didn't see it on the website) would be on par if not slightly better than the 250w hps. There is actually a completed grow comparison on another forum (pm me for link) that does the 200w diamond series vs a 250w hps and the led had better yields. I would stand by that comparison based on my own grows with them and would estimate they're somewhere between a 250w hps and 400w (maybe a 325 if there were such a thing). Both models run slightly under their advertised wattage. Think the 200w is around 180w and the 180w is around 165? Never actually tested them though, that's just based on what others have reported.

I can't speak on the Progrows because I've never used them. I don't know what the led companies are thinking when they make their comparisons and claims, but the only thing I can think of is they include cooling costs in those numbers. I can't speak on the $300 panels but I would say that if you get a $500 panel like I have, they will surprise you like they did me. I sold off my 600w hps before the end of last year right after I bought my second led panel. These things work, you just have to give them a chance and know you are getting a good light for the money you spend. But I'm not going to try to convince you because I'm just here to help and learn, just telling you my experience with them because you asked, and if you have any more questions let me know.

First time scrogging 32" x 96" cabinet with 2 Blackstar 135w and 3 2ft HTG "tek" t5s 110w each. Very happy with first scrog results considering I did not veg long enough to fill up the screen. Terrible fungus gnats in the way too hot MGMC soil. Basically first weeks of flowering was flushing the soil with every watering ph7.2ish very light nutes until plants stabilized. Nematodes and sticky cards took care of gnats. Could not believe I saved the plants much less came out with anything good but I did pull out 370G. Have since switched to all organic and second scrog screen is almost full enough to flip the lights. Also trying the 12/5.5/1/5.5 thing for the last week or so of veg. excited

Oh yeah 10 plants in those 2 gallon square white pots the first time. Thought I'd try something new. Don't know what I was thinking. This time 10 plants 4 gallons per. We'll see. Probably go bigger next time.

I guess maybe not too helpful on the LED only info other than I am happy with these 2 so far in my setup. For being so puny they did a good job.

I have the Blackstar 240 and I've got 2 plants in 3 gallon pots and 1 plant in a 1 gallon pot. Ultimately I think 2 is ideal for one light. I'm getting another blackstar in the next month so then i will have 2 240's in a 4x2x5 tent.

caesar23 said:

I have the Blackstar 240 and I've got 2 plants in 3 gallon pots and 1 plant in a 1 gallon pot. Ultimately I think 2 is ideal for one light. I'm getting another blackstar in the next month so then i will have 2 240's in a 4x2x5 tent.

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That's the exact tent and light combo I'm wanting to try!

supchaka said:

Originally Posted by caesar23
I have the Blackstar 240 and I've got 2 plants in 3 gallon pots and 1 plant in a 1 gallon pot. Ultimately I think 2 is ideal for one light. I'm getting another blackstar in the next month so then i will have 2 240's in a 4x2x5 tent.

That's the exact tent and light combo I'm wanting to try!

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Click my signature and profile if you're interested in this combo... I'm 3 grows in now with Lighthouse 2x4x5 tent and Blackstar240s from Gotham. IMHO 1-2 plants is ideal for a Blackstar240 depending on grow style. I grew 1 plant under 1 Blackstar240 for each of my first two grows, and right now I have 1 plant under 2 Blackstar240s. I jarred up over 3oz/plant of nice nuggs, and ended up with very high quality, frosty and dense cured medicine. I grow in a Waterfarm, so results will vary... I am going to scrog 2 plants under 2 Blackstar240s next. Good luck and Happy Growing!