Introduction to Induction Lighting

By Nate

As a medical user and avid gardener of cannabis for over ten years I have learned a lot about growing great medicine from various forums online, books, magazines and fellow gardeners.

Over this time we have seen a lot of hype in the horticulture products market. In some cases the hype is well deserved and in others clever marketing has fooled some into buying into failed technologies, etc. that don`t always give the yields and quality we expect.

In short they do not live up to the hype.

Having said that I am not here to create hype, I am here to share the knowledge I have gained after using a technology successfully for years.

Producing my own medicine is an important aspect of my life and keeping me moving and as such I would not compromise on anything that did not meet my high standards. To put it bluntly, if I was not impressed I would have sent my first induction light back and not thought about it again. I would also not be here today writing about them.

Induction Lights at first glance appear to be big fluores-cent bulbs but there are some major differences between the two technologies that make Induction lights much more intense, durable and much more appropriate from growing.

Here are some of them:

Induction lights use 60% less energy to produce the same amount of light as a MH or HPS.*

*(the actual energy savings could be more as less heat is produced requiring less cooling)

“The ability to use light-generating substances of higher efficiency that would react with metal electrodes in normal lamps.”

(http://en.wikipedia.org/wiki/Induction_lighting#Magnetic_induction_lamps)

• The bulb is a continuous tube with no filament. In a traditional light bulb

it is the filament that degrades over time. Since induction lights are filament free they last (100,000 hours) 7-10x longer than traditional HID lights (HPS/MH) and 3 x longer than LED’s.

Since there is no filament in the bulb, electromagnets are energized on each end of the bulbs and through induc-tion they energize the mix of chemicals in the tube turning them into a gas and releasing light.

Induction lights have a life expectancy of 25 years. Their Intensity degrades very little each year,

around 1% Bulb replacement after ten years worth of use is recommended.

Following any interruption in power Induction lights will turn back on right away, unlike High Pressure Sodium and Metal Halide which need to cool down first.

A separate area is not needed for ballasts as is the case with larger MH/HPS gardens increasing total growing area.

Induction lights are much safer and do not have the same risks as a hot HPS or MH system. No potential for broken or exploded bulbs and lower power usage means any fire risk is greatly reduced.

Although Induction Lights are a new thing to growers and the mass market, the principles for induction lighting have been around since the 1890’s and the times of Nikola Tesla. To make a long story short, starting in the 60’s, large companies started coming out with different types of induction lighting and since then many improve-ments have been made along the way. My introduction to the lights was through the Utility Industry. One of the places I grew up in replaced their street lights with this technology and I was given one to try as a grow light not long after.

I have been a legal medical user for more than ten years now and during this time have seen a few lighting tech-nologies that were supposed to revolutionize the growing industry and tried some myself. To say the least, I have always been a bit skeptical of new technologies before they have been tried by us, the serious growers who care about things like consistency, yield, and overall quality of product.

Induction lighting about four years ago, I set up a com-pletely different 4×5 room to accommodate the test. For my test, I was using a light meant for the utility industry, specifically something known as a “tunnel light” meant to be put in underpasses and tunnels but weatherproof nonetheless. The thing that immediately struck me about the light is how well it was designed to cross over into the greenhouse or indoor gardening industry. It basi-cally took many of the concerns that we as growers have and either got rid of them all together or mitigated their impact in a big way. Although it seemed cumbersome to work with being a bit large and a little heavy, that would only matter for setting up. Given that they are pretty much a panel of light I knew that I wouldn’t be moving plants around much, so their bulkiness was ok with me. Especially if it meant far less shadows due to light being produced from a panel rather than a hot spot of light as you get with a traditional HID light.

Prior to encountering Induction Lighting, I was given a giant 100Watt compact fluorescent bulb. I was told it would replace the 400Watt MH I had been using for many years without any issues. I trusted that advice and I went ahead and replaced my light. After a month or more of testing, it turned out to be the worst mistake I could have made. With a lack of heat and intensity, clones I had transplanted ended up stunted, they simply stopped growing and grew no extra roots. Before I had a chance to realize what was happening, I was running out of options and decided to put the healthiest ones into flower. In the end I kept the little sticks of bud (a few grams each) and hung them in my prep area for years as a reminder of what can happen when you just throw all your eggs in one basket like that. It taught me that I needed to test any new system or technology thoroughly and apart from the system I rely on to produce my meds. With this thought in mind, when approached to test

My first veg test went incredibly well. So well in fact, that I had trouble believing my eyes. I decided that it was time to really give this thing a shot. I found four clones that were virtually the same size. As can been seen in the pictures the plants were labeled with numbers 1-4. Plants 1 &2 were placed in the test room with a 200w Induction Light. Plants 3&4 were placed under my 400W MH. I took pictures daily of their progress. As can be seen by the pictures provided, the plants under the Induction Light become noticeably bushier in one week. After three or four weeks the differences between the plants were quite obvious. The induction light at half the wattage was producing plants with 2x more foliage. It was clear that the extra light coming from all angles made a big dif-ference in plant growth through the vegetative cycle of the plant.

So vegetative growth was much better but that repre-sents a small but important part of what we do. What really matters and where we use a lot more light is dur-ing flowering. Obviously, that is where my tests took me as I had to make sure it bloomed as well or better than the HID’s I was using before replacing them with this technology that was very new and virtually unknown to growers.

Of course this is also the first thing people ask; “It’s a great veg light…But does it bloom? Now, keep in mind, my original testing was done with lights that were 30%

less intense than what I currently use as they were not designed specifically for horticulture. Just to make it clear, YES even those lights do wonders in flower. In fact, I have had better yields since switching my entire setup to induction lights. It has now been that way for around 4 years. The great thing about the lights I am currently using is that they are more intense. So if I even had a hint that my plants could use a little extra light intensity before (which to be clear, I was happy with the old ones), any such hint is completely gone now that I am using a light made specifically for the professional hor-ticulture industry, resulting in a 30% increase in intensity.

Let’s examine these lights in a little more detail:

Temperature: These lights provide an appropriate amount of heat for what a plant needs to be healthy. If you are venting based on the fresh air needs of your plants then it is likely that will be enough to take care of the heat that is produced by these lights. Through experience I have learned that for a 4’x5’ grow, a 1000W HPS HID in a cool tube with the ballast placed outside of the grow area is comparable to a 400 Watt Induction Light with the ballast attached. The height of the room can also be reduced as you can grow within a few inches of your plant canopy, getting as close to an inch or two away from the light with-out your plants being damaged. In fact, with budding plants, I have often checked on my plants only to find that a newer strain I am testing has stretched unexpectedly into the light with little damage at all over the hours I had missed it.

Intensity: Induction lights designed for horticulture are on par with a 600W HID system when it comes to lumen output. The difference between the two is the surface area that the light is being produced from is much greater than that bright spot of light you get from an HID light. With a bright spot of light you get many more shadows. Induction lights on the other hand can be better related to a panel of light where the light is coming from a much larger surface area and thus able to come from all angles and penetrate the canopy of leaves much better. The effect, far less shadows and plants are wrapped in a more consistent amount of light. Light also penetrates the canopy much easier this way. This intensity comparison does not hold true for all induction lighting. Many of the lights on the market today belong to the lower intensity group of lights that were designed for people and lighting indoor and outdoor areas, not growing plants. Although they will work, they will not yield as well or penetrate as deeply into the plant canopy.

Spectrum: You can get Induction lights in a variety of spectrums but the ones I have been using produce full spectrum light. That means your plants get all colours of light and uses what it needs. If you limit the spectrum with a filter or go with a coloured light you are limiting the range of light your plant is getting. Why not provide the plants with a buffet of light and let them decide what to use. They will be healthier and you will see their true colour instead of a blue or orange tinted version allowing you to better determine the health of your plants. Lights that are coloured and not around 5000K can be consid-ered to be limited in their spectrum.

Total Amount of Light: Since the total surface area of the bulb is much greater than a 600W bulb you end up with more light, giving off around the same amount of light as a 1000W.

Small glass filling tube located at each end of the induction light tube.

Mounting Options: This is another area where not all lights are equal. When looking for an Induction Light, you may want to consider that some can be mounted from the side and others are simply not designed for that purpose. Many of the lights I have seen out there since I have been using them are flimsy, and/or not designed for the horticultural industry. I was also surprised that very few of the others, if any, could be side mounted to a wall.

Durability: These lights rate very high when it comes to durability when you get the ones that are meant to be durable. Lights that have been designed to be around a garden will have certain main features to look for. They are enclosed with glass so that the components and bulb are covered. The glass is important for two main reasons. Cleaning is much easier with one surface of glass rather than trying to clean the bulb, reflector, and parts inside. Although they are made from much heavier glass than a fluorescent, the bulbs have small nibs on them that remain from the vacuum system used to fill them. The ONLY issues I have seen with these lights have come from people removing the glass from them in an attempt to get more light out of it as there seems to be a misconception that adding glass will reduce light intensity in some circles. My answer to this misconception is that the lights meant for industrial applications were tested with a frosted plastic filter. This only reduced their intensity by approx 5%. Thus, a transparent piece of tempered glass only helps to direct the light downwards and focus its footprint a little better with very little light loss, if any. If you remove the glass you are also exposing the bulb, electromagnets, and other components to the elements. Let’s face it, you want to be able to spray your plants down if needed and not have to worry about getting your light wet as it could reduce the lifespan of the light compo-nents dramatically. Keeping your light clean is important as you will lose intensity if your glass gets dirty so you want a light that is easy to clean and will be durable enough for you to clean. As stated, the bulbs are a much heavier glass than is normally used in lighting but they are still glass and those two tubes that are used during the process of pumping the gases into the bulb stick out a lit-tle. These tubes can get caught on a rag or bumped while being cleaned and you have just ruined a pretty expensive bulb. The warranty will not cover that obviously.

Humidity: When there are less heat issues you have less humidity. There are a few reasons for this, for one, warmer air holds more water and the other is that HID systems tend to evaporate more water. As a result in smaller systems not controlled by AC you will notice that plants need less water and nutrient levels will have to be increased accordingly.

Cooling: For small scale gardens air flow is often enough to keep things cool, for larger grows one or more air con-ditioners is common. This equipment can get very expen-sive and running it is not cheap either. Induction lights use less power and produce much less heat than compa-rable 1000W systems. This means your cooling capacity drops meaning you can reduce your cooling equipment costs dramatically at around 50% less. Gardens are cheaper to set up and use less power when they are oper-ating so in some cases these lights can pay for themselves right away by not having to invest in more air condition-ers up front.

Retrofitting current setups:

If you get the Induction Lights designed properly for hor-ticulture you will end up with an effective footprint of about four feet by three feet. It has been my experience that the suggestions in the industry of a 400W induction being a good replacement for a 1000W are misleading. On a 2000W 4×8 table, due to the footprint of the light, you would have to add an additional light to cover the area in the middle that the Induction lights are unable to properly cover or move the plants daily to make sure they each get enough light. That third light adds more to youryield and you end up getting much better results. The good thing about the Induction lights is that if you are willing to use 2000W on a 4×8 table normally and you want to maximize your yields even more, you can use 4, 400W induction lights as their lower heat allows you to add much more light. You would be saving 400W of electricity and getting much higher yields with more con-sistent light distribution. Room height can be lowered as the lights are able to get much closer to the plants and give off less heat. This can often allow for one room to be stacked on another.

What to watch out for: Lights not designed to be in damp locations. A good light will say that it is and will be covered with glass. You have to wonder about lights designed without a glass cover if the ones that are specifically say not to remove it

When I initially got into Induction lighting I was using lights that were meant for street lighting or “tunnels”. These lights were the most appropriate of the styles I had to choose from. I just finished a tour of Hydro stores in central Ontario. Many of the lights I saw were either under designed for the serious grower lacking adequate durability and intensity or repurposed industrial lights. Most of them were intended as alternatives to HID’s in warehouses and have been repurposed as grow lights with either an attempt to create an appropriate hood, or simply sold as is as a “high bay” light.

If you try one of the repurposed lights, be ready for 30% less light intensity. Given the fact that these lights start out 30% more intense and that there is around 1% decrease in light intensity per year, after 25 years, if your light is still working, it will likely be more intense than some of the ones being sold as “grow lights” right out of the box. The repurposed lights are not all that durable. Some, such as the “high bay” light I mentioned (some-thing you would see in a typical big box store for light-ing) dent extremely easily as well as bend and warp if not handled gently (not something you want to be working around when literally bumping into it could cause it to dent). The others are simply under designed with less intense bulbs, no glass and a flimsy reflector.

Buyer Beware: They always say beware of imitation products, a phrase that could not be more true when it comes to choosing quality Induction Lighting. A high quality light is sure to last longer and be much easier to look after than one that has been under designed or is less intense than it could be.

Tip: Although these lights can be side mounted, they should be kept horizontal. If they are put up on one end at an angle greater than 20 degrees for more than an hour or so then they should be left horizontally for at least 24 hours prior to use.