Posted in Gardening & Backyard Farming, Sustainable Homes and Living

LED grow lights vs Fluorescents

We have been growing microgreens for a few years now and are in to our 3rd growing season for our Friends & Family Microgreens Club.  We have been using T5 and T8* Fluorescent lights since the beginning, but the old T8’s are only used in a pinch. Seeing as we have changed pretty well all of our home lights to LED’s now, we thought we better start looking into changing out the lighting we use to grow our microgreens as well.

I belong to a microgreen growers group on Facebook and this question comes up over and over again. What type of lighting should I use for growing microgreens? I’m sure the group admins pull their hair out every time it gets asked…

As with anything, there are many different answers to this, based on several parameters. What is the budget? What level of grower are you – Personal use only, Growing Club, Start-up Entrepreneur, Large-scale Commercial Grower or something in-between.

As Growing Club members, we need to keep our budget to a minimum, as we are not a profit centre. Because of this, we started looking at LED tape / strip lights, which come in a roll and run on low-voltage. There are mixed reviews on these lights, with concerns of safety, quality and growth of plants on one side and loving the low power consumption and ease of setting up on the other.

Because of this we popped into our local LED lighting shop to see what they might offer. Canadian Wholesale Lighting supplied us with 2 different versions of LED grow lights: The tape or strip light I was thinking of, along with a package of 5 – T5 LED Tube fixtures.

What did we compare?

  • Ease of use
  • Energy use
  • Quality of Microgreens, including:
    • Taste
    • Visual – Colour / Growth / Volume

Ease of use / Energy use

The TopLED Strip Light comes with cord / transformer and mounting brackets, but has no in-line switch. This means you would have to use a power bar as switch, as we have done, but if not using that growing shelf one growing cycle,  you have to unplug the light. Not a big deal, but a little less convenient.

As we were just doing a test, we used cable ties to hold it on to wood hangers. This will have reduced the efficiency a bit, as strip curled around each end. In proper install, we would cut to length and attach with cord connectors. Light is a Red / Blue at 4 – 1 ratio. 1 – LED Strip light tested at 38 watts


TopLED Strip Light

The T5 LED Series Tube fixtures are boxed as a set of five 280mm x 10mm LED strip lights built in to reflective tubes, with a power cord / transformer / switch, connection cords which allow for one power cord to run a series of fixtures and brackets. Very easy set-up. The light is very hard on eyes, so we mounted them on lowest grow shelf. If you were using this style in larger install, I would recommend wearing UV eye protection. 5 – LED T5 Tubes tested at 27 watts


T5 LED Series Tube fixtures


Our existing 60cm / 2 ft. Sun Blaster T5 Fluorescent lights are in their 3rd season. They also came with power-cord / switch,  built-in ballast, connection cords which allow for one power cord to run a series of fixtures and brackets. Tubes can be replaced as needed.  4 – T5 Fluorescents tested at 84 watts total.


T5 Fluorescent Lights

Quality of Microgreens

Now to the part you have probably been waiting for. How did the microgreens grow under the 3 different lights?

We grew three trays of each, making sure they were all given the exact same conditions. All were grown in 10 x 20 trays (standard greenhouse tray size), using certified organic ProMix container mix.

The grow room was kept at a 20 C / 70 F temperature (we keep it cooler then some growers as we work on a 2 week cycle).  We grew Sunflowers and a Brassica mix. All trays were put under light on day 5, which includes a day for Sunflowers to be soaked before planting.

During the first cycle, the approximate height from top of soil to bottom of lights were as follows.

  • LED Strip – 27 cm / 10.5 inches
  • LED Tube – 24 cm / 9.5 inches
  • T5 Fluorescent – 22 cm / 8.5 inches (our standard height for these)

During the second cycle, we lowered the LED’s hoping to get better results

  • LED Strip – 18 cm / 7 inches
  • LED Tube – 14 cm / 5.5 inches
  • T5 Fluorescent – 22 cm / 8.5 inches

How did they grow?

You will see below, that there is a considerable difference in volume and density of the crops. The two types of LED lights had quite different success with each variety of Microgreens, while the T5 Fluorescents remained more consistent.

Sunflowers

Sunflowers        T5 Fluorescents          LED Strip / Tape Light         LED T5 Tubes

Sunflowers        T5 Fluorescents          LED Strip / Tape Light         LED T5 Tubes

Brassica Mix


Brassica Mix       T5 Fluorescents          LED Strip / Tape Light         LED T5 Tubes

Brassica Mix        T5 Fluorescents          LED Strip / Tape Light         LED T5 Tubes

Taste Test

We did a taste test at end of second cycle. A very experienced tasting team, which included two family members and myself 😉 We did a simple 1st, 2nd & 3rd rating system. The results are as follows…

Sunflowers

  1. LED Strip light – Nice taste, good water content
  2. T5 Fluorescents – Not a lot of difference to above, just a hair behind
  3. LED T5 Tubes – Very bitter. We used in a smoothie.

Brassica Mix

  1. LED T5 Tubes – Nice taste, good water content
  2. T5 Fluorescents – Not a lot of difference to above, just a hair behind
  3. LED Strip – Limp. No appeal

Final Conclusion

It seems that the different Microgreen varieties fared differently with the different lights. All I can really say is that you will have to try out which Microgreens grow well under your lighting. The big difference for most of us will be the cost to buy and cost to run.

The LED Stip lights should be the least costly to buy, as you can easily take one 5m / 16.4 ft strip and cover a 4 ft. shelf. The LED T5 Tubes used the least amount of power, but I don’t really think that the five tube package covered all the plants on 4 foot shelf that well.

The T5 Fluorescents used considerably more wattage, but are quite consistent in growing a good crop. If you are growing a few trays for yourself, the overall cost wouldn’t be that much. If growing on a larger scale, that cost would add up quickly.

We definitely would need more time to really make a proper conclusion. 

*We didn’t use one of our old 4ft T8 Fluorescents as part of this test, but just for fun, its power was rated at 54 watts for a two tube fixture.

Posted in Gardening & Backyard Farming

Garden ideas – staging

Staging for growing peas and beans
Staging for growing peas and beans

We have some old staging that my Dad gave us many years ago. It’s not safe for working on anymore, so we were trying to decide what to do with it. Then we thought, why not make use of in the Garden! By using two ends and one cross bar, we created a great frame for our peas and beans to climb up on. The space inside allows for other ground or low growing crops as well. Great adaptive re-use of something that has been sitting around in the weather for ages.

We still had another staging left over, so our Daughter and Son-in-law created a a great little greenhouse for us at the back of the shop. The tomatoes love it in there! You can see the drip hose we are using. The emitters are supposed to be less likely to clog up with dirt. Seems to be working great so far 🙂

We keep talking about building a more permanent greenhouse, but so far this has worked out for us, so no hurry. Saves a lot of money as well!

Tomatoes love it in the greenhouse!

Simple greenhouse from old staging