First post in the forum. I’ve been growing for about 16 years mainly outdoor. I lurked the old OG also.
Started indoor a couple years ago using 1000w’s HPS’s with magnetic ballasts. Later on I switched to 400w Phillips HPS with Lumatek electronic ballasts for efficiency.
I’m seeing a lot of discussion and contradictory information on the efficiency of LEDs vs HPS vs CMH and I’m trying to clear the waters. If I’m making the full switch and investing a couple thousand I might be sure of what’s working better. I’ve seen side by side grows on forums and either some are poorly done without any kind of scientific method approach or they are biased. The cannabis industry is looking more and more like the fitness supplement industry with a lot of big brands marketing things with incorrect data.
In your opinion what is the most efficient light source when comparing gram per watt of dried weight? (Power consumption vs grams of dried weight)
After we figure this out we can proceed to: 1.cost of buying a HPS + reflector + ballast VS cost of buying a led unit 2.durability of HPS vs LED unit 3.growing method used since LED lights have less light penetration 4.heat generation 5.security of operating LED vs HPS 6.potency of the end product 7.taste of the end product 8.aroma of the end product 9.bag appeal of the end product 10.time to finish the budding process
Other factors and advantages such as heat emission, potency, cost of the equipment, etc are not to be compared. If some lights have better spectrum, etc is also not important. We will focus on gram per watt exclusively on this discussion and keep it focused around this subject.
Let me know about your personal opinion, links to properly done side by sides, etc…
Even though I run HPS and I have no intention of changing any time soon, the answer is clear that LED produces much much more grams per watt of power.
What LED does not have is the penetrating power of HPS as it is further from being a point source so the lumens are spread over a larger area.
If you grow in the classic top-down manner and adopt the techniques for growing with LED that mitigate this, like stripping upper fan leaves and so on then LED is a clear winner, less heat, more light, less power.
I run vertically with lights central to an outer core of plants and I need lights which take up the smallest space in the middle of them. As such LED is problematic for me and I will be investigating a LOT more before I consider changing.
On top of this, LED tech is a rapidly changing field right now, HPS is mature and does not change as quickly. The best HPS light from 2 years ago is still pretty much the best HPS light. Not so with LED lights. There are bright minds at work designing new fittings with new LEDs in them, some are here on the site, and these are coming out relatively often. This is something to consider.
What is not so certain is grams per square foot, or grams per week per square foot. When using these other methods of determining efficiency it is not so clear cut.
But within the limits of this thread’s discussion, being grams per watt, there is no doubt. LED is roughly twice as efficient as HPS to produce 1 gram of dried bud.
EDIT : I am unfamiliar with CMH so I won’t talk about them
thanks a lot for your input and for being concise with your answer.
That’s one of the things why I still do not invest in leds. The units are always changing and the grow tests are not keeping up. I would be pissed if I invest in a unit that leaves me more or less happy and then 3 months after something much better comes out.
Would you say that leds are good at a SOG with small plants since it doesn’t have a good light penetration such as an HPS?
What led unit would you advise me looking into? What’s your favourite HPS atm?
I will probably look for the “best” possibly unit atm and set it up agains the “best” HPS atm.
This is my first season with the new lighting. It is taking some getting used to, but I think I am getting it together. The thread above starts out with the end of the HPS lighting here.
Yes. I would say that is where they would shine, pun intended. They seem good for even and cool light which is what you want if you want to keep your plants short.
The PAR or PPF number, expressed in micromoles (umol) per joule (watt) is the benchmark for lighting efficiency. HPS and CMH top out around 1.7-1.9 umol/joule, LED goes up to 2.7 umol/joule.
The umol number is a guideline and doesn’t entirely count the improvement from a better spectrum - more red and blue and less green/orange is more powerful on the plants. CMH is a better spectrum than HPS IMO and good LED’s have even better spectrums. I think you will find most people like LED better after a few days and are getting rid of their HID lights after the first harvest.
Not to mention bulb replacement. My dad has been using the same bulb for over a year. When I suggested he replace it he argued that it was so expensive.
Im doing some tests on cheap LED strips, after reading the Samsung LED chip everyone seems to use, is from 2015.
Figured due to the price of LED “Grow lights”, I would see how far China is with copying them. I am mainly aiming to use LED for veg!
Im used to HID lights, and my flower room is running 2x 600 Watt HPS.
Im doing a flower test on my LED’s, just to see what the GPW will be like on these Ebay DIY lights.
My location requires the heat from HID lights, I fear with LED in my flower room. I would need to heat it, most of the year and only benefit from them 3 months during summer.
I plan to change my HPS lights to CMH’s, and remove my cooltubes. To save money on wattage in flower, and keep the better pennetration you get from HID.
Unless my LED test blow me backwards, and it so effective that it won’t matter that I need to heat the room. I still got my reservations, but I have to say LED have come a long way!
good that’s what I’m looking for I don’t really think I need light penetration. Have you got any kind of LED you recommend? I’m currently looking into the the samsung line.
For the look where this is going I believe more and more LED’s are the future. The only drawback is I think the market if full of bad and expensive LED units which is causing a lot of controversy. If we filter the real efficient ones and bring them to better prices either by DIY or outsourcing then I believe we will all win specially people with heat problems also.
this is a good point and after I’m decided with which ones does better at strictly gram for watt I will look into:
1.cost of buying a HPS + reflector + ballast VS cost of buying a led unit
2.durability of HPS vs LED unit
3.growing method used since LED lights have less light penetration
4.heat generation
5.security of operating LED vs HPS
6.potency of the end product
7.taste of the end product
8.aroma of the end product
9.bag appeal of the end product
10.time to finish the budding process
LED, Samsung mid power chips are the in thing right now. COBs are last week, purple LEDs are so last season.
If you are buying lights pre-made, it is difficult to beat Fluence. HLG and ChiLED make decent pre-fab units as well.
If your into DIY there are the Solstrips (what I use along with several others here), quantum boards, and the ChiLED Logic pucks. All use the Samsung LM561C LEDs in different form factors.
DIY is the way to go and we could start building our own pannels or crowdsource a company to do them if they indeed work well. I have a friend who understands a lot about LEDS since he works with them I will try to get some info on it. I will also look closely at your thread to see where it goes. I keep hearing about the samsung LEL’s everywhere.
I run as efficient of a garden as I can and have used hps mh in the past and after swapping out the fat bulb for pcb boards I can say without a doubt I’ll never use the hid ever again in any capacity.
The better led still gives off heat it’s not completely cool, but compared to those 20thousand kelvin bulbs it’s night n day.
I replaced a 400w mh in my experiment cab with a 240w meanwell that I keep dimmed to approx 170w
I was able to remove the jet engine exhaust fan and now use a 4” cpu fan and my temp is never above 82
this is exactly what I was looking into right now. Once I figure out which LED unit stands on it’s feet I will test it against HPS. LED business is going forward pretty fast.
If we can find what works best here and bring the price down by DIY we will strike gold.
Going to look for side by sides with these DIY samsung chips.
I’m also seeing some interesting threads on CMH, anyone got input on that vs LED?
For me the reverse is true. I use narrow beam angle LEDs - they have 90 degree beam angle, it penetrates better than my 600w Gavita HPS. beam angle can vary from 60 or 70 degrees all the way up to 150, it makes a huge difference in the way the light works.
If you match the right amount of intensity (PAR or PPF) to your canopy area you will get excellent penetration. There really is no downside except price. Quality LED’s will cost more upfront than HID.
very very interesting!