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How To Pick A Grow Light

How To Pick A Grow Light

 

 

Factors to Consider:

 

-Crop Yield

-Quantity of light

-Correct balance of colors to steer crop

-Crop Quality

-Plant morphology (compactness, leaf size, leaf thickness)

-Pigmentation (color)

-Nutrients (antioxidants, vitamin C…)

-Desired Application

-Photoperiod extension

-Work lights

-Location of Installation

-Indoors sole source lighting

-Greenhouse supplemental lighting

-Proximity to crop

-Ability to control heat (AC)

-Power supply

-vertical or horizontal

 

Recommendations to Apply the Science:

 

-Picking lights for supplemental vs sole source lighting environments

-Mixing light sources

-Changing light sources by crop stage

-Target specific light intensity

-How to position grow lights

 

Product References: **This video will cover EVERY light in greenhouse and grow tent**

 

-VGS Grow Rack

-4x4 Stand, Light Hanger, Low Profile Corner Legs

-Agrobrite Desktop Plant Light

-Active Aqua Stand, Light Hanger, Low Profile Legs, and Flood Tables

-Autopilot PX1

-Solar System 550, Solar System Controller, Solar System 1100

Welcome to Episode 10, the final episode in the Plants and Light series. It’s time to pull it all together and talk about how to choose a grow light.

 

Application not always powering plant growth (get the couple of the less common situations out of the way first)

 

Controlling Photoperiod

Might want to use a red light to inhibit flowering or far red to promote flowering, check back to episode 2 photoperiod and episode 7 far red for more information on this topic.

 

-Work lights. Sometimes the lights aren’t for plants at all, it’s so the grower can work with the plants. Then you’d be looking at a green light.

 

-Plant Growth, or steering plant growth with light quality

See following sections. And sometimes lights are used for controlling photoperiod and plant growth.

 

First by location:

-Indoors sole source lighting or Greenhouse supplemental lighting

 

Light quality has a greater influence on growth in sole source environments than in a greenhouse. This doesn’t mean quality should be ignored, but often the focus is on light intensity when choosing a supplemental grow light for a greenhouse.

 

-Proximity to crop

 

Then there is proximity to crop. In a greenhouse, the lights can be place high up so you can use powerful lights without worry of frying up your crop, but if you are growing in a place with low ceilings or in a grow rack with multiple levels, you’ll want to select a lower intensity grow light, or a dimable light. T5s and LED bars are great for vertical gardens with multiple levels. For lights that are mounted high above the crop, it is important to select the correct reflector. Some reflectors have a wide spread but some have a more directed light delivery, they can be mounted higher and still get deep canopy penetration. Reflectors can also affect light intensity.

 

-Ability to control heat (AC)

 

Also under the umbrella of location, is what kind of heat load can the location handle. If indoors and using AC, the AC should be sized appropriatly for the heat load created by the lights. It may be necessary to select lights that don’t generate much heat, like LEDs, if growing indoors with limited cooling ability.

 

-Power supply

 

And then the power supply. Some lights can be run on three-phase power, this is not the standard 110 or 120v wall outlet, this is more powerful, it could be 208v, or 240v, or 277v, or 480v! Lights pull less amps when running on higher voltage. The power bill will be lower when running lights on a higher voltage. The other consideration on power supply is, is there enough power for the lights?

 

**Research the amperage required to run the lights at the available voltage , that means a lower power bill.  The available power supply at the location is also important. Can the location provide enough power**

 

 

-vertical or horizontal

 

And the final point under location is how to mount the lights. Some growers like mounting lights vertically, this is popular with living walls, but not all lights can be mounted vertically. LED bars are a popular option for vertically mounting.

 

Crop

-Crop Type - Microgreens, Leafy Greens, Flowering Crops

Plants don’t fall neatly into these three categories, but they are a good general guide.

 

-Crop Stage -  Propagation or Vegetative or Flowering

 

This is similar to crop type, but this would be adjusting the light by stage of growth, generally a practice with flowering crops. This could be a low intensity light for cuttings or seedlings. Or selecting a specific spectrum for leaf development then changing the spectrum to add color to the crop later in it’s development, or adding UV at a key stage in development to increase terpenes and flavinoids. Lighting specific to crop stage can either involve moving plants from room to room with different lights in each room or using a programmable light with adjustable spectrum. Or Some ballasts have the ability to run either MH or HPS, and often growers use MH during vegetative growth and HPS during flowering, and sometimes using MH during the end of flowering too for the addition of UV (Show sunburst). Preparing transplants for outdoors


 

-Plant morphology (compactness, leaf size, leaf thickness)

 

Sometimes a grower wants a very short plants to sell so it can be shipped more efficiently, take up less space, so they’ll control the growth of the plant with lighting to keep it short, usually selecting more blue and eliminating far-red light. Or a grower might want to add weight to their leafy greens, they can get thicker leaves when using more blue light. Or a grower might be selling a living head of lettuce that needs to fill up a clamshell, and they want the head to have large leaves so it fits nicely, then they might want to include a bit more red in the spectrum for leaf expansion. Or a grower might want a taller plant cause it’s easier to graft, or take cuttings, or selling a cut flower with a long stem, all reasons to add far-red to a light recipe. (talk about balance beam and then mention how blue can just stomp on the side of the balance beam affecting ratio of red to far red)

 

-Marketability of the crop, which can often depend on Pigmentation (color)

 

What’s the ‘bag appeal’ of the crop. How does it look packaged when harvest. Do the colors of the crop make it attractive to the consumer. A red lettuce, should have red leaves. For pigmentation a grower may want to add some blue or UV to the spectrum, not all crops require a light recipe with blue or UV for pigmentation, but it can help. And there are other ways to increase pigmentation, often related to temperature and sometimes manipulating nutrients.

 

-Nutritional Value, Flavor, Smell

Pigmentation generally includes increased anthocyanin, the red and purple pigment. This can increase the nutritional value of the crop. For flavor and smell, usually the approach to improve these with light is the addition of UV at key stages of development. Climate management also has an effect on these as does nutrients and a bunch of factors, but UV can quickly deliver results. Less than a couple days of UV can improve flavor, smell and nutritional value.  


 

Budget?

This is a tricky topic. Some lights have a lower upfront cost but require frequent bulb changes to maintain intensity, while others are more expensive upfront yet maintain intensity longer. And warranty offer should also be considered, any quality light manufacturer should off a warranty on their products.

 

So, there is a lot to consider, and there is no one correct answer. Just check out the online grower forums to see endless arguing over the best grow light option. But there definitely are some ways to narrow down the choices to find what’s right for you and your crop. Thank you for watching the Plants and Light series, if you enjoyed this it’d be real nice if you subscribed to the channel and checked out some of my other videos. I’m often posting content on my Facebook, Instagram and Twitter before it makes to YouTube, so give that a look too. And join the mailing list on FarmerTyler.com, and I haven’t use that mailing list yet, but someday I’ll figure out how that thing works. Alright, if you’re still around by this point you really deserve a thank you! Thanks, I’m Farmer Tyler, and the more you know the better you grow.

 

Recommendations to Apply the Science:

-Picking lights for supplemental vs sole source lighting environments

-Mixing light sources

-Changing light sources by crop stage

-Target specific light intensity

-How to position grow lights

 

-VGS Grow Rack

-4x4 Stand, Light Hanger, Low Profile Corner Legs

-Agrobrite Desktop Plant Light

-Active Aqua Stand, Light Hanger, Low Profile Legs, and Flood Tables

-Autopilot PX1

-Solar System 550, Solar System Controller, Solar System 1100