Why HPS over CFL?

[Perfect Sun LED]

Are there benefits one way or the other? Let's find out.

First, keep in mind the rule of inverse square law. The lumes you read for say a 400 watt HPS at 50,000 is only for the first foot, because lumes is the foot power of a candle. Every foot after the first gets weaker by 1/4th. So if the 400 watt HPS is 2 feet away from the bud, then the bud only received 12,500 lumes. If it is 18 inches away, or 1.5 feet, then the bud received 25,000 lumes.

Okay, so, now let's compare CFL and HPS.

Say we have a 4x4 tent, and we want all of it to receive great lighting. First with CFL there is no reason to buy higher then the 23-26 true-watt 100 watt comparison 1600-1700 lumes because they produce the most lumes for the watts used. For example, a 300 watt (64 used) only delivers 4200 lumes, where as 3x 23 1600 lumes bulbs delivers 4800 lumes. The 300 watt bulb cost $16-17, and the 100watt ones cost only $2.50, so $7.50 for 3 of them, which out preforms the 300 watt. Save money and use more 100 watt cfls.

Anyway, to light a 2x2 square foot area of our 4x4 tent with 100 watt cfls, we need to use 8 of them, which only is good for 1/4th of our tent, so we would need 8x4 cfls to light the whole tent. Insane.

The 2x2 area uses 8 cfls, which only produces 12,800 lumes. Theory says if you keep them within 1 foot of the buds, then the bud should be receiving 12,800 lumes. The problem is that CFLs don't penetrate very well, so it is better to keep them within 6 inches of the buds.

Get this. Just 1 200 watt HPS puts out 22,000 lumes, and that is good for up to 1 foot away. The 200 watts you can place within 1 foot, i think, without burning. I know you can put a 600 HPS 18 inches or 1.5 feet away with no issues.

Now, if you place the 200 watt HPS 1 foot away, it will not cover the very outer buds. Those buds are about 1.5 feet away, so they receive 11,000 lumes.

See how much more lumes your buds receive with the 200 watt hps vs the 8 CFLs? Why 8? Because 8 CFLs use 184 watts, if they are the 23 watt ones, and 208 if the 26 watt ones. In other words, you are using the same amount of watts as the HPS, yet getting only half the lumes.

And because the cfls should be closer, the outer buds suffer even more. On top of that, because you have 8 bulbs all bunched up together, they are having to add their lumes together, which doesn't really work out the same as one bulb. Anyway, the point is, you get twice as many lumes to your buds with the 200 watt hps, and use the same amount of power. Your power bill remains the same.

What about cost?

HPS 200 watt bulb = avg $10. The ballast is about $50-60. You can get away with just airing it with a fan, or you can use a cheap 4inch inline and dryer hose. Cheap.

CFLs x8 = $20. You also need the housing where the bulbs screw into. Each of those cost $3.43 or so at Home Depot. You need x8 = $27 or so. Already you are at $47. Now you need to make a good. If you do it with the wood scraps at Home Depot, like I did, then the wood is about $2-3. Then you need the sheet metal on top, at least one top, if not on the sides, and that runs about $5. We are getting close to the price of the 200 watt hps, which is twice as good, at least twice as good for lumes.

Okay, but what about the quality of the light. HPS comes in 2100k, just like cfls come in warmer K. Will CFL offer more useful light then if both are 2100k? I don't think so, but I could be wrong. A full spectrum LED might deliver more useful light, though.

So either way, you would be using up 800 watts of power to cover the whole 4x4 room. However, I think you could get away with just using two 200 watt or two 300 watt HPS 2100k bulbs. You would just need to lift them a tad higher then 1 foot away from your buds. And don't use the very outer edges of your tent.

I will add a picture in just a second. Need to reboot.

The bummer thing is, I already bought and made cfl hoods, and bought a 300 watt led. I know I will not get the same amount of buds this way. Sure the LED will add extra light, but I need to use at least 1 300 watt HPS instead of the CFLs. I'm thinking either two 200 watts or two 300 watts HPS.

I was going to use 12-16 cfls, but it just will not yeild as much bud, and 16 would use almost 400 wats anyway. Might as well run two 200 watt HPS.

 

[Hosebomber]

While you made a great attempt in this post you have a few key elements wrong.

First, a lumen is not "the foot power of a candle". It is the measurement of the total amount of visible light given from a point source in all directions. Candela is in a single direction. The equation to get lumen from candela in a sphere is 1 cd·4π sr or roughly 12.5 lumens per candela.

Second, If you place your CFL's at 6" from the plant (which they should be) you will have closer to 19500 lumens. See Inverse square law for more info.

Then there is the fact that you are comparing HPS and CFL watt for watt and lumen for lumen. Neither of those are the correct ways to calculate lighting for your plants. You want PAR or photosynthetically active radiation. You need approximately 65 watts of CFL lighting to produce the same PAR as 50 watts of HPS lighting. So while your basic math was close to right, you was missing the reduced par. Therefore, your 2x2 area would actually need 11 26 watt CFLs to be comparable to a 200 watt HPS. One area where you would gain improvement is that you could position the CFL's closer and around the grow area better than simply hanging a single point source over the top of them. Placing the 8 (or 11) CFLs in a bundle over the canopy would defeat the one benefit you would gain from having them.

As for your 300 watt LED, if it is of good quality, you could nicely cover a 3x2 area with it. A few CFLs in the corners of that area as side lighting would greatly increase your yield.

 

[Perfect Sun LED]

hose bomber if what you say is true about the lumens of cfl increasing because it is 6 inches from the plant instead of a foot, i.e. the lumen rating for the bulb is for 1 foot away since it goes back to comparing it to the candle foot, then if a 200 watt hps was 6 inches away it would produce much more than 22,000.

Then the problem of putting 8-11 cfls 6 inches away doesn't let all the bulbs add their lumens and consentrate it on any one bud. With the hps, those center buds are all getting 22,000.

I got a luxmeter coming in the mail. I will test my cfl hood and led at different hights to see how well they preform. If the CFLs do as poorly as I think they are, then I will get a 400 watt hps to cover 4 plants, while the led will cover 2, plus a few 200 watt cfls.

 

[Perfect Sun LED]

I wanted to add this info, as I think it is important.

200 watt HPS, produces 22,000 lumes, not 55,000; that's a 400 watt hps.

Butt, yes, lumens are important. A bulb with 90-100 percent PAR (percent of relative energy) per NM at 22,000 lumens is going to grow a plant more efficiently than a bulb with 90-100 percent PAR with 11,000 lumens.

A good hps bulb produces 90-100 percent PAR within the ranges of 580-610nm. That is warm usable light by a green plant. They put out 80 percent of 560-570nm, mostly green light however. So the most type of light an hps of 2100k puts out is yellow. Pure yellow (620nm) is about 40 percent. So 40 percent of 400 watt hps, 51,000 lumes is 20,400 lumes. When you get into the orange and red, you drop to 10 percent and below.

cfl isn't going to change much if you are running a 2100k cfl or around that like 2500k. Try to find some charts showing CFL percent relative energy per wavelenght or relative spectrial power or relative intisity per wavelength in nm, like 520nm, 620nm, etc.

Even a full spectrum CFL doesn't offer much more.

 

[Hosebomber]

I believe you are missing the entire point of PAR and the photo active spectrum. Only about 40% of the total output of an HPS is within the the action spectra due to the extreme intensity of the green and yellow that is above the max absorption spectra of a plant. (Theory only here) If you have a 400 watt HPS putting out 55000 lumens and a monochromatic LED of reds and blues using 200 watts, you will receive more PAR from the LED panel.

Likewise you are missing the point on lumens and foot candles also. Lumens are in no way connected to candela or foot candles other than you can mathematically convert 1 to the other. You can do the same for almost every other measurement unit.

Again, PAR measures visible light 400-700nm and is scaled for photo absorption of plants. So the things that make HPS very high in lumens (green and yellow wavelengths) makes them have a very low PAR value.

 

[cgkone]

lets be honest, cfls are bunk as fuck,hps is good but its HOT and fragile. LED is the shit but its hella expensive. Im out here in NOR CAL so i got to grow bomb. And in the summer it gets to be over 100 degrees regularly, so LED is worth the price. Im not just practicing, im forever gunna need weed so long term i nedd something that lasts. i just bought an LED and its the size of a laptop and dont even hot.

 

[Perfect Sun LED]

I believe you are missing the entire point of PAR and the photo active spectrum. Only about 40% of the total output of an HPS is within the the action spectra due to the extreme intensity of the green and yellow that is above the max absorption spectra of a plant. (Theory only here) If you have a 400 watt HPS putting out 55000 lumens and a monochromatic LED of reds and blues using 200 watts, you will receive more PAR from the LED panel.

Likewise you are missing the point on lumens and foot candles also. Lumens are in no way connected to candela or foot candles other than you can mathematically convert 1 to the other. You can do the same for almost every other measurement unit.

Again, PAR measures visible light 400-700nm and is scaled for photo absorption of plants. So the things that make HPS very high in lumens (green and yellow wavelengths) makes them have a very low PAR value.

It's like I said in the other post, HPS has 100 percent of 600nm, which is pure yellow. However, pure yellow is used by marijuana plants. Only if your leaves are mostly yellow, which can happen, would yellow not be used very much. Hps, also produces a lot of green/yellow, about 90 percent. So, yes, in theory it seems like LEDs should out preform an HPS if the LED had the same watts, but I've never seen this in experiments. HPS always produces bigger buds, and slightly more bud, if the test is controlled. Same mother, same clones, same environment, same nuts, same medium, etc.

I haven't seen CFL even compete in such expirments. LED holds up, though. It might be do to the fact LED don't produce UV radiation, which might also be why bugs aren't attracted to them.

I haven't looked at many experiments for MH vs HPS for flowering, but from what I have seen, they seem pretty equal as far as yeild.

 

[Perfect Sun LED]

lets be honest, cfls are bunk as fuck,hps is good but its HOT and fragile. LED is the shit but its hella expensive. Im out here in NOR CAL so i got to grow bomb. And in the summer it gets to be over 100 degrees regularly, so LED is worth the price. Im not just practicing, im forever gunna need weed so long term i nedd something that lasts. i just bought an LED and its the size of a laptop and dont even hot.

I was born and raised in Cali, only in the last three years have I lived in Oregon. Man, you should take advantage of outside grow, even if in a green house during grow season. My uncle just yielded 3.5 pounds a plant, indica, outdoors in Cali. My grandpa in Humbolt pulls 2 pounds easy off indicas. I can only imagine what they would get off a mostly sativa.

 

[Hosebomber]

It's like I said in the other post, HPS has 100 percent of 600nm, which is pure yellow. However, pure yellow is used by marijuana plants. Only if your leaves are mostly yellow, which can happen, would yellow not be used very much. Hps, also produces a lot of green/yellow, about 90 percent.

100% 600nm what? what does it have 100% of.... That is the point you are missing. You are looking at a relative intensity output spectra. At that bulbs peak output is at that nm wavelength. I can make a 20 watt LED that puts out 100% relative power in the 660nm range and have 95% 430nm blue by making it a 11 to 9 ratio. That doesn't mean it has 100% of the maximum amount of red light the plant can absorb or needs. Just that it is relatively 100% for that light.

So, yes, in theory it seems like LEDs should out preform an HPS if the LED had the same watts, but I've never seen this in experiments. HPS always produces bigger buds, and slightly more bud, if the test is controlled. Same mother, same clones, same environment, same nuts, same medium, etc.

It has been my experiences that LEDs do beat HPS watt for watt. I'm very close to my goal of 50% of the HPS draw for production of the same (roughly) quantity and higher quality under LED lighting. There are many grows here and on other sites and youtube in which you can see a side by side for LEDs and HPS grows. LED nearly always wins.

 

[Perfect Sun LED]

I would like to check them out to see how controlled the tests where. If you have any links, please share, as it can be hard to search these forums for specific subjects like that, at least it has been for me.

Do LEDS beat hps watt for watt as in the watts pulled or the watts outputted? Like my 300 pushes 300 watts, 100x 3w diodes, but pulls 168w or something.

But, yeah, you are right, a weak 100 watt cfl could also have a 100 600nm, for example, but that will not grow a plant as well because it is not as bright, so there is not as much of that 600nm hitting the leaves. This is why I was saying that lumens is important, not just wavelengths. The only time a lamp with tons of lumes would be useless if it was pure green.

 

[Hosebomber]

Do LEDS beat hps watt for watt as in the watts pulled or the watts outputted? Like my 300 pushes 300 watts, 100x 3w diodes, but pulls 168w or something.

That means your 300 watt LED manufacturer lied to you and told you they was selling you a 300 watt LED and sold you a 168 watt LED.

There is no possible way that a LED panel can pull the wattage of the number of diodes x claimed wattage of an led. LEDs are rated 1 watt = drive current of 350mA. 3 watt = 750mA. 5watt = 1amp. Voltage varies and the following numbers skew when you get into the 20 and 50 watt (multi-array leds) but blues and whites run around 3.1-3.5 volts red run around 2.1-2.6 volts. Multiple the voltage of the LED by the drive current and you get the actual wattage pulled. Likewise, you never run the LEDs at their max rated current or you will have thermal issues as well as shortened lifespans.

 

[Perfect Sun LED]

To my knowledge, LEDs are supposed to produce more watts using less power, just like cfls do. 100pcs x 3watt diodes, should be 300 watts. I was wrong about how much power it uses. It says 182-196w.

I wonder if stealth grow also lies about their lights. For the SG602, it says this right from their site.

•Wattage: 600 Watts;
actual power draw 400 watts*

It would be strange if they lied as they are sponsored by this site. Let's check another sponcor. If it only pulls 400w, can they really claim it is pushing out 600 watts? If LEDs use less energy to produce more power, then sure they can. But that means the one I have could also produce more power than it consumes. Not sure if it pushes a true 300 as claimed, though, because that means they are pushing the diodes fully, maxed out, which would seem like it would take more energy, but perhaps it works that way with how many amps they use or whatever.

Advanced LED lights.

Their DS300 says 150x3w diodes, so they run them lower to be a 300 watt system, and pulls 274, much higher than the SG, I guess. But still, both of them do run their diodes lower than the one I bought, which is good, so the sg600 actually has enough 3w diodes to be a bit over 800w.

The DS pulls is much closer to the power claimed to be produced.

Oh, new LEDs are rated 3 watts, and good ones only use one chip, as claimed by both Advanced and DS.

 

[Hosebomber]

To my knowledge, LEDs are supposed to produce more watts using less power, just like cfls do. 100pcs x 3watt diodes, should be 300 watts.

Watts is the amount of power being draw... not the amount of light being released. LEDs are more efficient than any other light source. This means for the amount of power (watts) they use, they put out more radiometric flux (light energy). The most efficient LEDs are close to 40% efficiency. In comparison, regular light bulbs are about 1.5%-2% efficient and CFLs are about 7%-10%. A theoretical 100%-efficient lamp would be about 680 lm/W. The best LED gets 170 and there is a test produce at 240 currently. THe best HPS gets 153 lm/w and a cfl gets about 50-70 lm/w.

It would be strange if they lied as they are sponsored by this site. Let's check another sponcor.

Stealth Grow LED is not a sponsor... Grow Stealth LED is. They did a great job of copying a existing companies name and logo to get initial sales. Sadly, they didn't put as much effort into creating a better product.

If it only pulls 400w, can they really claim it is pushing out 600 watts?

Sure they can. They can claim whatever they want... The fact is, they use a poor marketing ploy to lure people into buying a product thinking they are getting something they are not.

Advanced LED lights.

Their DS300 says 150x3w diodes, so they run them lower to be a 300 watt system, and pulls 274, much higher than the SG, I guess. But still, both of them do run their diodes lower than the one I bought, which is good, so the sg600 actually has enough 3w diodes to be a bit over 800w.

The DS pulls is much closer to the power claimed to be produced.

Advanced took the advise of myself SteveHman and a few others on this site and started renaming their products closer to the actual power draw than what what was then standard number of diodes x diode labeled power. I believe they even started putting the actual power draw on their site as well, but I honestly haven't looked lately.

If you refer to my post above I give rough numbers for what the actual draw of each diode can be. If they run their diodes at 350mA and 750mA or more they are driving them too hard and it will increase heat, decrease output, and shorten the lifespan of the panel.

 

[Perfect Sun LED]

Grow Stealth can probably sue for that. Hey, they make an even greater claim.

So are you saying that LEDs cannot produce 300 watts of equal light unless they pull 300w? What about CFLs? Do you think when they claim to pump out 150w equal that they actually are, even though, they only pull like 32w?

What I have found with CFLs is that you need to draw the same watts as an hps to even try to compete with one.

 

[Perfect Sun LED]

But yeah, GS still calls their 300w led a 300w even though it pulls 240w.

 

[Hosebomber]

Watts are not a measurement of output. It is a measurement of input. But to answer what you are saying... You would have to draw 750 watts of power to output "300 watts". They are 40% efficient at best. For CFLs you would have to use over 3000 watts to get those same results.... they are 10% efficient. The claim that a 32 watt CFL is equal to a 150 watt incandescent light bulb. 150/32= 4.6875 times more efficient is the claim there. Which if you refer to my post above, incandescent bulbs are 1.5-2% efficient. 2 x 4.6875= 9.375% efficiency. A believable claim.

Calling their 240 watt draw a 300 is a lot closer (80% of claimed) than the SG602 claiming 600 watts and drawing 400 (67% of claimed).

 

[Perfect Sun LED]

Ah, I see what you're saying. That makes sense.

I am still searching for big bud grows with led only.

 

[Hosebomber]

The overall length of a single cola will not be the same as with HPS or even MH... It is a penetration thing. Light loses it's intensity the further away from the point source it gets. Those large single colas are the result of a number of factors from penetration to shade avoidance to spectral distribution. The key with LED grows is to produce more colas of higher quality. The end result is the same or more mass/weight and more resin production. Few will argue the fact that LED grows better quality. This is due to the greater photosynthesis rates and higher nutrient reserves during the flowering period.

 

[Perfect Sun LED]

I ordered my 400 watt hps, so I will be replacing the cfl hood I made.

I will still use like two 200 watt cfls to fill in gaps.

1 400 watt hps, and 1 200 true watt LED.

What I have learned from this thread is that LED will not help on your power bill if you want to grow equal to the amount of an HPS. LED will help when it comes to heat. However, if you are growing in a cold garage in the winter time, then you want the heat of an HPS.

During the summer, the HPS poses more problems because you have to vent the heat. Both have their ups and downs, I guess. HPS are still way cheaper even if you have to buy a 6 inch intake fan and 6 inch ducting. Just use the inexpensive dryer stuff. 6 inch 200cpm or better fan can be bought for under $50 on ebay. It's just a plain metal fan and tube, but they work. I will be replacing my home made ones soon.

IMPORTANT: If you are on any sort of budget, then don't go with LED. They do not pay for themselves by saving you on your power bill. If you are using a LED that pulls 250 watts, then you can get more buds by just using a 250 watt HPS. Worst case, you get the same amount of buds. But the only reason to get the 250 watt hps and not a 400 is because you want to save on your power bill. The price between a 250 and 400 are very close, so if you don't mind the slightly bigger power bill, then go with a 400. A 400 will give you even more bud.

CFLs will not save you much money either, unless you grow with a small amount of them, but then you are limited to growing one or two plants. You will do better just focusing all the energy on one plant and try to get 3-6 ounces from it.

The minimum amount of 100w CFLs for one plant to come close to acheiving that is 8. Even then, you want to use LST to get max yeild, IMO. CFLs seem to work pretty good for veg, from what I've experienced thus far, so you could make a veg room with them, no problem.