Combining LED with HPS or CMH advice please.

[bishbashbotany]

Does anyone have any experience combining LED with HPS or CMH? I got hold of one of DIYLEDs new PAR+465pro LED lights from the guys for a very reasonable price. A beautifully designed piece of kit and have seen a couple of members starting to get some great results with them.

 

I originally planned to use it in a 1.2 x 1.2 x 1.8 Hydrolab tent (low ceiling) but since decided to go a bit bigger with a 1 x 2 x 2m tent and cut it down as it suits the space bigger and obviously a bigger crop:)

 

Apparently the 465pro is best suited for 1 x 1 spaces so initially thought I'd fork out for another. However I've since been reading that there are problems with LEDs and temps with some members struggling with them. I'm setting up in an unheated building so I reckon I could be in for trouble. It's probably a bit too much of a stretch for another 465pro so thought I'd start off by combining it with either HPS or CHM. A cheaper option which will help generate more heat.

 

I guess I would have the PAR+ one side of the tent and a 600w HPS dimmed down to 400w or a 315w CMH the other. Does anyone have any experience of doing something like this and could I run into problems? Also as the aim would be to create as much heat as possible would the HPS be more beneficial? I've no experience of CMH. I guess I could also have the LED panel in the middle with smaller bulbs either side. Possibly a better distribution of heat and light but starting to get complicated.

 

The other thing is that I'm planning on watering with blumats via a resevoir. I've been reading that plants under LEDs feed differently, could this lead to problems as well?

 

Any help would be appreciated.

[Lemons&Diesel]

Its a complete misconception that LEDs generate less heat that HID lights, normally spread by people who have never used LEDs before and dont have a clue what theyre talking about. 600 watts is 600 watts is 600 watts, regardless of where it comes from. Converting electricity to light is the exact same equation whether the light comes from a LED or a HPS or a CMH.

 

The main difference, and the reason people think equivalent LEDs run cooler, comes from the fact that LEDs both run more efficiently, and are cooled much more efficiently. So if it takes 600w of HPS to light your space, you can get away with maybe 300w of LED. Half the power consumed will generate less heat no matter where it comes from. In addition to that, LEDs put their heat down differently and are rarely a single massive bulb sitting in the middle of a grow space. My current 600w LEDs are 40'x40'. You can touch the heatsinks on them no problems and there is very little heat coming off them. I still have the exact same trouble cooling my space with 1200w of LED as I did with 1200w of HPS.

 

I have grown with both on a few occasions and I didnt run into any trouble. I cant see how running both in combination would give you any problems that either alone wouldnt also give you. Also, they dont "feed differently" under LEDs. Plants are just a bit hungrier for calcium and magnesium. Easy enough to supplement so correctly installed blumats will work wonders.

 

Good luck whatever you decide to go for regardless.

Edited April 14, 2021 by Lemons&Diesel

[Guest]

I have run Blurple LED with HPS, CMH with HPS, CMH with new style LED, and new style LED with HPS.... Think i have covered everything?

 

  So many variations that I can hardly even remember them all, and mainly out of just tinkering, wasting money, or trying to solve a problem that wasn't really there  

 

Every time i did this i always ensured that i matched whatever lights i was using as best i could so that you could keep all lights roughly the same distance from the bulb. Otherwise one unit might have to be higher that others, and this would mean its light pattern might be blocked by a lower light. For instance i ran a singe 315w CMH, with 2 Mars Hydro SP300s (300w) on either side of the CMH. Wasn't exactly enough light for my space but I got a relatively even light spread.

 

You always need this think about where the energy is going and also try and get as even a spread of energy as possible. Because the Mars hydro's were long and thin i felt it best that they went on either side of the CMH. 

 

Any other questions just ask, but i am far from a pro. I just like to tinker  

 

Also absolutely nothing to worry about mixing spectrums. As above I have done lots of variations. Just a case of getting the best even spread of energy for your space.  

Edited April 15, 2021 by Moonstone420

[Sasquatch]

I'm using LEDs and I'm getting atrocious nute bleaching problems. I'm thinking of getting a CMH ballast - maybe a dimmable 315w or a 150w, the LED light is a ChilLED Logic twin puck frame and I would hang the bulb vertically without a reflector in between the pucks.

It might be possible to keep up to nutrition with LEDs but I'm having to bombard them with extra feeds and cal/mag and I still get dying leaves . Ask yourselves this - are the  plants we get under LEDs actually much better than mature plants under CMH or even sodium? OK so LEDs give better yields of tastier buds but getting them there is far more of a ballache under LED and plants don't end up any bigger, so I'm planning on maturing them under CMH then turning the LEDs up to get the benefits for the buds.

 

GE and maybe Phillips do 150w E40 CMH bulbs and there are digi ballasts as well as the old SON ballast/ignitors, I'm thinking this might be enough non- LED light for me for about £100 less than a 315w plus bulb. 

[EarLobe]

It isn't a misconception. LEDs, especially the newer more efficient ones, do convert less energy into heat and more energy into light then there older counterparts. Maybe the old LED lights didn't but newer ones will produce much less heat and you can Google this and see this information on any decent LED light spec sheet.

 

As for the heat and the issues. There is speculation that it is something to do with the infrared heat not warming the leaves but I could literally contradict myself with my utter lack of knowledge here so I won't try and explain what I dont know lol.

 

What I do know is I have to raise the temps by about 3 degrees at the moment otherwise my plants start showing all signs of crap.

 

Best advice would be to have a run yourself and see what happens. I can't imagine many have tried what you're proposing.

 

Atb mate

 

E2a. Seen lots of videos online of people combining different types of LED lights with different spectrums. Cant imagine this would be any different except you would have a bulb that produces a little more heat? 

 

Definitely worth a side by side experiment imo....

Edited April 15, 2021 by EarLobe

[ratdog]

On 14/04/2021 at 1:11 AM, Lemons&Diesel said:

Its a complete misconception that LEDs generate less heat that HID lights, normally spread by people who have never used LEDs before and dont have a clue what theyre talking about.

 

 

ok bud

 

i have a 600 par+ and the temps were silly low in a 1.2 so i added a chm 315 and that was ok but not high enough, so added another for now, temps sat at a perfect 29 and they love me again. i will hopefully remove one of the cmh but the end of the month, we will see, but come the next heat wave the par+ will be doing the business

[Lemons&Diesel]

Not sure what the rules about posting links offsite are. The guidelines dont really makes it clear if its any off site links, or just commercial off site links that arent allowed. If im breaking any rules, mods just let me know and ill delete them.

 

5 hours ago, EarLobe said:

It isn't a misconception. LEDs, especially the newer more efficient ones, do convert less energy into heat and more energy into light then there older counterparts. Maybe the old LED lights didn't but newer ones will produce much less heat and you can Google this and see this information on any decent LED light spec sheet.

 

It is a misconception. According to the best data we have available at this present moment in time, the luminous efficacy of commercially available LEDs is approximately 50-138, while the luminous efficacy of HPS is approximately 50-150. People can argue against the fundamental laws of nature all they want, but the Laws of Thermodynamics exist. 600 watts is 600 watts is 600 watts. It doesnt matter where it comes from. And a single watt is equivalent to 3.41 BTU/hr.

 

https://www.researchgate.net/figure/Evolution-of-luminous-efficacy-performance-of-white-light-sources-Commercially-available_fig17_228841897

There are also multiple factors at play that change the way we perceive the heat in our tents. One of the biggest differences between both sources is in how they put their heat down. Heat from LEDs is exhausted by heatsinks at the back and is pushed away from plants. Heat from HID is thrown in all directions and gets trapped at canopy level. We as growers tend to put our extraction at the top of our tents, enabling much more efficient extraction of LED heat, while the heat from a HPS has to rise to the top of the tent to be extracted, all the while the bulb is throwing down more heat which again gets trapped. We also tend to put our thermometers at canopy level, reading the heat that becomes trapped there much more. All of this is due to the nature of the bulbs. LEDs individually contact a heatsink. The heat is removed from the back of each individual diode with a heatsink. So there is a lot more heat being pulled off directly at the point where it is generated. While the HPS bulb is inside a reflector, which directs even more of the heat directly onto the top of the plants. Due to the fundamental nature of LEDs, it is far easier to create a heatsink that is much more effective. Thats why when people measure heat from one or the other they get confused and say watt for watt the HPS produces more heat. It doesn't. It just can't be as effectively managed. If you took the same watt for watt LEDs with no heatsink or fans at all, you would end up with a similar result. Although because the heat is spread across a much greater area with LEDs, it's still likely that the HPS would be the more effective radiator. And all this is before we even touch on the fundamental differences between radiative heating, and convective heating.

 

Here is an excellent video from MIGRO showing this exact thing inside a completely enclosed space. Notice the difference in temperature is only 3 celcius, but he is using 210w less energy on the LEDs. The thermal image at the end shows everything I have just explained beautifully.

 

https://www.youtube.com/watch?v=7qw2BvGhhN4&t=62s

 

5 hours ago, ratdog said:

 

 

ok bud

 

i have a 600 par+ and the temps were silly low in a 1.2 so i added a chm 315 and that was ok but not high enough, so added another for now, temps sat at a perfect 29 and they love me again. i will hopefully remove one of the cmh but the end of the month, we will see, but come the next heat wave the par+ will be doing the business

 

Im not sure what this proves other than youre growing in a cold room.

[EarLobe]

But the fundamental point is the tent is colder with an LED? And this completely skirts over the fact that it takes energy to produce both light and heat yet pound for pound LEDs throw Bulbs out the water.

What you posted while true ignores the fact that grow rooms in the winter, with LED, indoors, need auxiliary heating to keep things good. Incandescent bulbs keep things a bit sweeter when it's cold.

 

You can't tell a whole forum that they're imagining the temperature drop because infact they produce the same heat. I got a 600w oil radiator and I'm sure as shit that gets hotter than the LED too...

Edited April 15, 2021 by EarLobe

[ratdog]

1 hour ago, Lemons&Diesel said:

Im not sure what this proves other than youre growing in a cold room.

 

 

no shit

 

e2a, but anyone who thinks leds heat a tent like hps/cmh is deluded, hps ect worked before for me, mostly too high temp wise, why doesn't led?

 

if you need to add more heat then non led lights are a very good way imo

Edited April 15, 2021 by ratdog

[badbillybob]

7 hours ago, ratdog said:

 

 

ok bud

 

i have a 600 par+ and the temps were silly low in a 1.2 so i added a chm 315 and that was ok but not high enough, so added another for now, temps sat at a perfect 29 and they love me again. i will hopefully remove one of the cmh but the end of the month, we will see, but come the next heat wave the par+ will be doing the business

this.. above...is correct

 

the OP did say he was going to be in a cold building

 

LEDs are much lower temps than HPS, from experience of using both. 

i had a 480 led in my shed tent and couldnt get temps over 19, so added a hps = 25, perfect

Edited April 15, 2021 by badbillybob

[Lemons&Diesel]

1 hour ago, EarLobe said:

But the fundamental point is the tent is colder with an LED? And this completely skirts over the fact that it takes energy to produce both light and heat yet pound for pound LEDs throw Bulbs out the water.

What you posted while true ignores the fact that grow rooms in the winter, with LED, indoors, need auxiliary heating to keep things good. Incandescent bulbs keep things a bit sweeter when it's cold.

 

You can't tell a whole forum that they're imagining the temperature drop because infact they produce the same heat. I got a 600w oil radiator and I'm sure as shit that gets hotter than the LED too...

 

No. The point is different parts of the tent are heated differently by the two lights. The total thermal mass units is the same. Did you not watch the video? 1 light heats the top of the tent, away from the canopy. 1 light heats the bottom of the tent, right where the plants are. But the temperatures are almost identical, even thought 210w less energy is being used with the LEDs. And im not telling anyone theyre imagining anything. Im telling them they arent measuring correctly. And I posted a video showing exactly how and why, but you dont actually seem to have watched it for some reason.

 

43 minutes ago, ratdog said:

 

 

no shit

 

e2a, but anyone who thinks leds heat a tent like hps/cmh is deluded, hps ect worked before for me, mostly too high temp wise, why doesn't led?

 

Are you unable to comprehend English or did you just not bother reading anything I wrote? A good part of my post explains that LEDs dont heat a tent like HID, and why. That doesnt change the amount of heat they produce. This isnt rocket science. Go watch the fucking video and see it shown with your own eyes. Your incredulity means nothing when people can see what I said is correct by simply watching the video I posted.

Edited April 15, 2021 by Lemons&Diesel

[Lemons&Diesel]

29 minutes ago, badbillybob said:

this.. above...is correct

 

the OP did say he was going to be in a cold building

 

LEDs are much lower temps than HPS, from experience of using both. 

i had a 480 led in my shed tent and couldnt get temps over 19, so added a hps = 25, perfect

 

This above is not correct.

 

LEDs are the exact same temperature as HPS, from experience of using both. Anyone can do that but it proves nothing. I had 2 600w HPS in my tent. I now have 2 600w LEDs. Temperatures at canopy level are slightly different, but temperatures in the room where they are vented are the exact same.

 

So you had a cold shed. What exactly does that prove?

 

You dont have to believe what I say. Go watch the video I linked. See with your own eyes how wrong you are. It shows you exactly in red and blue and green why we perceive HPS as being hotter, but if you look at the actual temperature of the hotspots created, they are almost identical, even though he is using 210w less LED. Look at how the LED heat leaks from the top of the tent into the surrounding room, but the HPS heat sits down on the floor at canopy level. If people still cant accept that, then thats their own problem.

 

And as to the OP being in a cold building, so am I. I just use the heat from my lights to heat up a 20x10 enclosed room that I then have my 8x4 tent in. There has been 0 difference in temperature in the bigger room since I changed my lights. The only real thing that has changed is that I no longer have pedestal fans blowing over my canopy, and I instead have them blowing directly over my LEDs .

Edited April 15, 2021 by Lemons&Diesel

[badbillybob]

im just going off my own experience, which was as i listed it earlier. 

you can sit here and try and convince whoever you like, but i know my tent, i know my lights and i can read a thermometer.

i took my temperatures at canopy level (i.e. where it matters)

 

And since its pretty universally accepted by the entire growing world (apart from yourself), that LEDs run cooler, watt for watt than HPS, its pretty pointless me adding anything else. 

 

[EarLobe]

Once again you've missed the point mate.

 

And people don't sit in their cars with a hose from the exhaust to the window for a reason...

 

[Davey Jones]

Just now, badbillybob said:

And since its pretty universally accepted by the entire growing world (apart from yourself), that LEDs run cooler, watt for watt than HPS, its pretty pointless me adding anything else. 

 

 

Its marketing thats convinced people!

 

Aside from the fact that HIDs can produce as many lumens as pointed out above fuck marketing people its really not hard to grasp

 

First law of themrodynamics says energy cant be created or destroyed, only converted. WE convert electrical energy to light ande get heat as a by product. How many lumens (or whatever measure of illumination we use) we get dictates the so called efficacy. More lumens per watt we want as we get a brighter light and grow bigger plants hence a HID is more efficient at lighting an area than say a fluorescent. More bang for the buck Its why we choose the light!

 

Regardless of how much of teh initial energy was converted to light, that light carries energy and its trapped in a room bounving off the walls and you know what happens when photons are absorbed? They heat things up its why the sunshine is warm on yout hand

 

The whole energy used is converted to heat, whatevr the input power is is what the heat load is. It applies to every light technology. The heat with LEDs like discussed is spread out over a greater volume just like a fluorrescent tube, cooler touch temp as its physically larger and the heat is easier to manage because of this reason but power consumption is work done and basically speaking work done is the amount of energy converted to heat!