How To Compare Grow Lights

[jumpincactus]

You got any pics as a reference. Never really seen a coral farm. Hear about em more now that I grow.

late getting back sorry. No pics bro. Been years and were lost in a hard drive crash. My boy @rmoltis can attest to my reef tho.

 

[rmoltis]

late getting back sorry. No pics bro. Been years and were lost in a hard drive crash. My boy @rmoltis can attest to my reef tho.

It was a nice reef. I remember him being worried about the power going out and having 100 gallons go everywhere.

 

[fatawa]

You make it hard to judge lights @jumpincactus...lots of rules....lmao.and reef talk.ha.how u want to judge then?amps×life length?

 

[fatawa]

I can b the Ginnie pig for hps lights..i kno most guys use led's....aka dim lights..lmfao.jk...just a hps guy threw n threw

 

[jumpincactus]

You make it hard to judge lights @jumpincactus...lots of rules....lmao.and reef talk.ha.how u want to judge then?amps×life length?

the info was just for each person to have a way of determining for themselves so they can make informed decisions. I personally am not sold on LEDS yet. HPS for the win. But when you get into efficiency and cost savings even with diminished yields LED tech is beginning to look more and more attractive as an option. My main concern is battling and paying for heat control here in the desert where daily temps hit 110-115 deg

LEDS even with professional growers and greenhouses are still being used as supplemental lighting for low light demand plants. But as time goes on and the industry makes improvements more and more folks will turn to LED to cut their ongoing operating costs. The fact of the matter is leds are a wiser choice when it comes to those that feel bad about their "Carbon Footprint" I have always felt is was a waste to use lights that I then in turn have to spend $$$ to keep my enviro spot on. When the upfront cost comes down and the yeilds get closer to mh/hps that will be my trigger point for making the jump.

 

[dollardos]

1. Is this a ok green bulb to use
2. Does anyone have an opinion on this igrow light

 

[Leew421]

1. Is this a ok green bulb to use
2. Does anyone have an opinion on this igrow light

You get what you pay for. Make sure to check reviews. Green light when lights are out is a bad idea. Plants actually use green light.

 

[dollardos]

You get what you pay for. Make sure to check reviews. Green light when lights are out is a bad idea. Plants actually use green light.

So when I need to work in the dark like spraying or when I'm behind. What's the best way to go about it. I've used green light don't know I was doing it wrong

 

[Leew421]

So when I need to work in the dark like spraying or when I'm behind. What's the best way to go about it. I've used green light don't know I was doing it wrong

Just spray or do whatever right before the lights go off

 

[learningrowa]

Ok so I have a question - is there any preference on spectrums or based on your experience are you only looking for the PPFD and PAR values? Is the trend in growing overall going to full spectrum and not doing red and blue like some folks are pushing a lot? I have looked at Spectrum King and Fluence and other full spectrum solutions and just wondering who is the winner overall today?

 

[MIMedGrower]

So when I need to work in the dark like spraying or when I'm behind. What's the best way to go about it. I've used green light don't know I was doing it wrong

I use a green 15 watt cfl twisty light to see in the flower room during lights off. I have accidentally left it on overnight even and have never seen a problem.

Another grower had an led green light that was much brighter than mine and he had flowering issues.

A low green light won't hurt anything in my experience. My light controller has a green led display that dimly lights the room as well. Titan light controller.

 

[jumpincactus]

Ok so I have a question - is there any preference on spectrums or based on your experience are you only looking for the PPFD and PAR values? Is the trend in growing overall going to full spectrum and not doing red and blue like some folks are pushing a lot? I have looked at Spectrum King and Fluence and other full spectrum solutions and just wondering who is the winner overall today?

With any lighting, the fuller the spectrum the better. Then next consideration is canopy coverage. You want something that will spread that PAR as evenly as possible across your canopy. From corner to corner and edge to edge. To my mind PPFD and spectrum supplied are the 2 most important items. ...........my .2 cents

 

[jumpincactus]

I use a green 15 watt cfl twisty light to see in the flower room during lights off. I have accidentally left it on overnight even and have never seen a problem.

Another grower had an led green light that was much brighter than mine and he had flowering issues.

A low green light won't hurt anything in my experience. My light controller has a green led display that dimly lights the room as well. Titan light controller.

Green light used on and off for short periods will not affect flowering cannabis. But I still do my due diligence to get all my work done so when it's lights out I dont have to go back in with any light. Green or otherwise.

 

[GT21]

You get what you pay for. Make sure to check reviews. Green light when lights are out is a bad idea. Plants actually use green light.

Neither chlorophyll A or B absorbs green light

 

[MIMedGrower]

Green light used on and off for short periods will not affect flowering cannabis. But I still do my due diligence to get all my work done so when it's lights out I dont have to go back in with any light. Green or otherwise.

I am really never in there during lights out anymore for any length of time like you caution but I am still thinking the intensity of the green light may matter. I don't think they can "see" my controller led display or the weak cfl single bulb overhead. it's like 5' away and only 15 watts. We can see it but maybe not the plants.

 

[MIMedGrower]

Neither chlorophyll A or B absorbs green light

I can't remember the process. But it was proven plants absorb green light and use it.

But it wouldn't affect the flowering cycle as I remember.

Do you use one?

 

[GT21]

I can't remember the process. But it was proven plants absorb green light and use it.

But it wouldn't affect the flowering cycle as I remember.

Do you use one?

No... i dont mess with plants at night... i know how photosystems 1/2 and chlorophyll a/b work.

 

[GT21]

http://scienceline.ucsb.edu/getkey.php?key=1110

Green is more powerful than a lot of color and it blends to blue and yellow well but a true green is pretty useless to a plant..and this is not going into anthocyanins

 

[MIMedGrower]

http://scienceline.ucsb.edu/getkey.php?key=1110

Green is more powerful than a lot of color and it blends to blue and yellow well but a true green is pretty useless to a plant..and this is not going into anthocyanins

Here's some more.

http://msue.anr.msu.edu/news/green_light_is_it_important_for_plant_growth

This has a ton of research and info.



I have been really interested in this stuff ever since I saw the improved results from adding the 315 LEC to the hps already in my flower room.

As for green spectrum.

Seems it depends on the plants environment how it uses the green light. Research is all over the place.

 

[TrubldBreeze]

As a refresher, PAR (Photosynthetically Active Radiation) is a region of the electromagnetic spectrum (400 to 700 nm) that promotes photosynthesis. PPF (Photosynthetic Photon Flux) is a critical metric that tells us how much PAR a light-source emits. PPF does not measure PAR at a specific location (e.g. your crop canopy), but it tells you how many photons within the PAR region are coming out of the light-source every second. PPFD (Photosynthetic Photon Flux Density) measures the amount of photons within the PAR region at a specific location (e.g. the amount of light delivered to your canopy) every second. If you have a PAR meter, it is reporting PPFD (μmol/m2/s) measurements. You must understand the differences in these metrics before you can compare various horticulture lighting systems. Many manufacturers realize this can be a confusing topic, so it is very easy for companies to mislead potential customers with exaggerated marketing claims, misleading information, and by showing a limited set of (or using blatantly wrong) metrics. However, once you understand the differences in these metrics, you will be able to cut through all the ‘marketing’ and ‘hype’ and simply ask manufacturers to provide the data you need to successfully compare lighting fixtures.

In order to explain the correct method for evaluating a horticulture lighting system, let’s first highlight some of the metrics used today that you need to avoid:

• RULE NUMBER 1: Don’t use electrical watts to compare grow lights
• RULE NUMBER 2: Don’t use lumens to compare grow lights
• RULE NUMBER 3: Don’t be fooled by a company that claims to have a magical growth spectrum
• RULE NUMBER 4: Don’t just look at a single PPFD measurement directly under the fixture
• RULE NUMBER 5: Don’t focus on the wattage of the LEDs used in the fixture (1W, 3W, 5W, etc.)

In general, if you see a company using any of the above items to promote their horticulture lights, run away and don’t look back. None of these metrics, nor their derivatives, tell you anything about the performance of a horticulture lighting system.

Rule No. 1: Don’t Use Electrical Watts To Compare Grow Lights
Many people use total electrical watts, dollar/watt or watts/square foot to compare horticulture lighting systems, but these metrics are 100% useless and will most likely lead a consumer to make a poor purchase decision. Why? Simple. Electricity doesn’t grow plants. Furthermore, radiometric efficiency (how much light a fixture emits per watt of electricity) can vary by up to 200% amongst the popular LED fixtures on the market today. Hence, since light (not electricity) grows plants, you need to ask how much light a fixture emits. It sounds simple, but 99.9% of horticulture lighting companies do not advertise this metric. Instead, they focus on electrical watts. Why? Because it is very hard to design an efficient lighting system (measured in μmol/J) that delivers high light levels, but it is very easy to build an inefficient lighting system that consumes a lot of electricity. High efficiency LEDs, power supplies and optics cost more than less efficient components, and many manufacturers use lower quality components to increase profit margins

Remember…You are not buying watts. You are buying a system that delivers light to grow your plants, so a quantitative measurement of light output and the efficiency in which the system produces that light is the critical metric you should use to compare the performance of horticulture lighting solutions.

Rule No. 2: Don’t Use Lumens To Compare Grow Lights
This one’s easy to explain. A lumen is a rating of how bright a light appears to the human eye. However, since human vision is not correlated to photosynthetic grow rates, total lumens is a dead metric. As a rule, if someone is trying to promote lumens for a horticulture lighting system, they should not be selling horticulture lighting systems.

Rule No. 3: Don’t Be Fooled By “Magical Growth Spectrums”
Many scientific papers have confirmed that all wavelengths from 400 to 700 nm (the typical PAR range) will grow plants. However, there is a myth that is widely propagated on the Internet that claims plants do not use green light. Many companies promote their magical growth spectrum by publishing the commonly-referenced Chlorophyll A and B absorption spectrum chart. Armed with this chart, they mention that plants are green, so plants reflect green light from the full-spectrum light source. Have you heard this one before? Without going any deeper into this topic, it is important to note that there is no magical spectrum that is going to allow a 50W fixture to replace a 1000W fixture because it only uses the “wavelengths that plants need.” While plants certainly have numerous pigments and photoreceptors across the PAR range, nothing will trump the need for delivering the required levels of light (PPFD) to your plants. Spectrum has a very real effect on plant development, but be cautious of a company that spends too much time talking about their special spectrum (especially if they do not spend equal effort in publishing their delivered PAR measurements). There is a short list of companies who manufacture commercial-grade LED fixtures for the professional horticulture industry, and none of them market the number of LED ‘bands’ in their fixture.

Rule No. 4: Don’t Look At A Single PPFD Measurement
Let’s take a quick look at Rule 4. Unless you are growing a small plant directly under your light, a single PPFD measurement doesn’t tell you much. By clustering the LEDs closely together and using narrow beam optics, it is very easy for a manufacturer to show an extremely high PAR measurement directly under the fixture. However, unless you are only growing one plant in this exact location, you need to know how much PAR is being distributed across the entire canopy. Since most LED lighting systems centralize the LEDs into a small fixture footprint, these systems naturally produce very high PPFD levels directly under the fixture. However, these light levels will drop significantly as you move the PAR sensor just a small distance from the main fixture housing. If you are growing over a 4’ x 4’ area, you need to review the PPFD levels over the entire area to calculate the average light level the lighting system is providing. If you only had a center point measurement you may assume a fixture is extremely powerful. However, you would need multiple measurements across the 4×4 grow area to calculate the average amount of PAR that is provided by the fixture. Light uniformity across the grow area varies greatly from fixture to fixture, and unfortunately, most manufacturers do not publish complete PAR maps. It is easy to produce high PPFD numbers directly under the fixture, but it takes a very powerful and well-designed light to deliver high (and uniform) PPFD values across an entire canopy.

Rule No. 5: Don’t Focus On The Wattage Of The LED’s
Do you use 1W, 3W, 5W or 10W LEDs? We are asked this question on a frequent basis, but the wattage of the LED does not tell you anything meaningful about the lighting system’s performance. Since LED and fixture efficiency varies widely, the wattage of the LED is not a meaningful metric. Remember, the LED wattage is a system input, and growers care about the system output. Hence, the LED wattage doesn’t tell us anything about the system’s ability to deliver light to your plants.

As a simple analogy, the LED inside a lighting system is equivalent to the engine in a car. By itself, the horsepower rating of the engine doesn’t tell you how fast the car will go. Pair a high-horsepower engine with a poorly designed transmission, and the car will not go very fast. Hence, as far as the driver is concerned, the relevant metrics for a car are related to the overall performance (e.g. 0-60 mph time, top speed, miles per gallon). Any reference to a component inside the car is irrelevant to the driver. It is the same situation with lighting systems. The amount of light delivered to your grow area (PPFD), the electrical watt consumption, and the light distribution pattern are the important metrics to focus on, so ask for more information if a manufacturer wants to focus on the type of LED they use.

Note: Since LED quality varies by a very wide margin, it is important to know the brand of LEDs used in the lighting system. There are a handful of world-class LED manufacturers, so make sure you find out what brand of LEDs are used in the lighting system. Assuming the fixture manufacturer has developed a reliable fixture design, higher quality LEDs should last longer if they are not being over-driven to achieve higher light levels.

Again, you are buying light to grow and develop your plants. In our opinion, you want to buy a lighting system that delivers the required amount of light to your plants for the lowest initial cost, while consuming the fewest electrical watts possible. Ask the fixture manufacturer to provide the following pieces on information: PPF, input watts, and PPFD maps for your intended coverage area. With this information, you can calculate: PPF/$, μmol/J, light distribution patterns, and uniformity levels.

Good article! Here's a good channel I enjoyed when researching lights
https://www.youtube.com/user/MonsterGardens/playlists