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Lighting: LED vs HID vs Sun etc

I would be interested to hear other professionals thoughts on different lighting systems.

We run a primarily outdoor and greenhouse operation but have some smaller indoor rooms. Some with LED (Marspro II) and some with HID - we are testing these more for off season production and mother plant and clone preparation for outdoor and greenhouse deployment in spring/summer.

We are developing plans for an integrated greenhouse (3000 sq+) with assisted lighting. Here in Canada we can have some pretty poor runs with the sun (there were 50 hours of sunlight in the last month for eg) for about 4 months of the year.

Has anyone else had experience with deploying a large assisted lighting system? Reflections on energy usage? Light spacing. What has worked and what has not worked so much?


I’m not an expert by any means, but I’ll relay the information I’ve gleaned from interviewing several growers:

  • Many growers feel that LEDs are almost to the point where they’re comparable to HIDs in terms of PAR output. That said, their cost is still significantly higher, so many don’t see them as worth the cost yet. You could balance that against the greater efficiency of LEDs and reduced heat output (significantly lower AC costs). You’ll have to balance initial costs versus ongoing costs.

  • HIDs (CMH for veg, HPS for flower) are the standard of the industry currently. A lot of people I’ve interviewed use Gavitas. For clones and seedlings, a lot of people use T5s or T8s, due to their lower intensity.

  • Not many growers use greenhouses/natural sun currently, but as the prices of cannabis go down, we may see that change. The operational cost of using a greenhouse will be much lower over time when compared to an indoor grow.

  • In greenhouses in particular, HIDs are better at projecting light over a distance (the “throw” of a light) when compared to LEDs. If you want more heat, such as living in a cold climate, HIDs also give you extra heat. LEDs require special lenses for distant lighting applications.


I would agree. From my very unscientific tests - the LED’s are close - they give a great result - not quite as much yield anecdotally, however the balance of having less energy draw and wattage draw on the powerboards is a big plus. I ca n have more lights with less draw and the new technologies are very exciting. I’ve been playing with them for about 8 years now - the latest Mars Pro’s have been pretty impressive and being able to control grow/flower with the flick of a switch is very useful.

The cool light of the T5/T8 is definitely my preferred choice for seedlings and clones.

I think we will find that as the market converges and prices drop there will be significantly more focus on lowest cost of production - and a well setup assisted greenhouse will have many advantages over a totally indoor operation. We are already seeing here in Canada where the big licensed producers (WEED etc) are investing considerably in greenhouse capacity.

As an example…

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Bumping this topic for the newer folks.


In the emerging global market - the sun and the equator will prove to be the lowest cost production models. Mass marketed cannabis extracts from the sub-tropics.


I agree, good old fashioned sunlight is the most cost effective, but what about states like Nevada which must be indoors, do you see certain light making a move (LED, Plasma, etc)


I think we may start to see fiber optic cables in indoor settings in places with naturally unfavorable conditions. That way you get the sun’s light without its heat, and you can control the humidity.


LED is by virtue of being a point source and not requiring a reflector to direct photons to the canopy will be a more efficient light source. Couple with that where innovative designs can morph PAR net action spectra to the canopy in a homogeneous bend of light that can be tailored to vegetative or flowering states in what we refer to Layered Plant Lighting, in other words the baseline vegetative spectra is always present in the spectral emission but as the plant moves into flower red -far red are added there is a more natural photomorphogenesis that is not found when plants are moved between two different light sources. Our latest LED design delivers an industry leading 2.4 uMol/watt as a broad spectrum. This allows us to utilize the Layered Plant Lighting technique and with that see faster conversion to flower while producing higher quality flower with comparable yields (documented) to higher wattage HID lights at less heat (2,100 btu/hr at High Flower setting).


Now add a plasma light to lets say a Gavita HID… new ballgame… PLUS now your getting UVA and UVB… strike 3 game over :slight_smile:

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Nathan - saw you were growing in a greenhouse and thought you should know of some game-changing greenhouse lighting tech, just released by LumiGrow.

LumiGrow just released a light sensor module that integrates with their professional smart LED fixtures and their cloud-based software system. The system works to measure ambient sunlight in the greenhouse, aggregate data, and hit daily light targets by zone (crop-type, variety, etc.). It’s smart lighting meets the cannabis greenhouse. And LumiGrow has a large install-base in Canada, so you’ll be among good company!

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