Hydroponic Grow Lights in the Far North

by Dave
(Igloo #7 North Pole-Lethbridge, Alberta, Canada)

Jason - coming to you with my problems I feel like your my "shrink". Perhaps you could start a whole new field & call it plant psychology. Anyway "doc", I finally hit some sites that totally discount most claims about the effectiveness of LED's, unless you spend thousands of bucks, & even then I could not find these "pieces of gold" LED's. I have a room 10ft x 10ft. In your opinion, what are the best MH/HPS bulbs/single or dual ballasts/reflectors?

I am going to start my indoor grow with soil, and once mastered I will "pop my cherry" and graduate to a DWC culture. Finally, is it feasible to try 24 hour growing? What problems are there, if any, using chlorinated water? That's all I've ever used on my outdoor garden. Has anyone ever had success growing indoor corn? Thanks - Dave

Answer: Dave- I answer questions from Africa to South America, and from Vietnam and Thailand to India....but it is always you folks up North that keep me on my toes! Your conclusions about the LED lights were the same conclusions shared to me by a frequent visitor and contributor to the site, Kev from the UK. I had pretty much reached this conclusion myself also, but Kev provided a bit of "first hand" knowledge that I had been looking for to either confirm or deny the effectiveness of the LED systems.

In a 10' x 10' room, I suppose there would be room for two 4'x 8' garden areas (kept just a small distance from each wall) and a three foot walkway in between for maintenance. Squeezing anything more into this space would be very difficult, and eliminating a walkway would be a mistake (you never know what is going to go wrong, need replaced, need extra support, etc.).

I almost always illuminate a 4' x 8' garden area with two 600 watt HPS lights, hung stationary and each centered over a 4' x 4' section of the garden. However, the same area can also be illuminated effectively by one 1000 watt HPS grow light on a light mover. This will at least give you an idea of how many pieces of hardware you will require, depending on which way you decide to go with this.

Most lights are pretty similar....I have seen great results with a number of very different reflectors. Mainly, you want a reflector that will actually reflect all of the light and direct it into the garden area. "Special" reflectors that claim significant increases in light to the garden area are really just advertising and marketing. For the most part, all of the special shapes, anodization, polished steel, and aircraft aluminum only produce marginal gains in light intensity....but they will cost you a lot in the pocketbook.

The main feature you want for maximum light output is to use a HPS light instead of a Metal Halide light....they produce significantly more lumens (usable light) per watt. After that, you want a light with a digital ballast. They use less electricity and produce more lumens by controlling the power to your light digitally. Third, you want to use Hortilux light bulbs. They really do produce more light than other bulbs, and are worth the few extra dollars (just my personal experience).

The reason I do not bother with Metal Halide lights is simple....HPS grow lights produce more lumens per watt, plants in the vegetative stage grow well under HPS light, and plants are only in the vegetative stage for a short time compared to the flowering stage. If you decide to try to grow 24 hours a day, choosing your crops will become difficult, and using a Metal Halide could be a consideration at that point.

When it comes to a reflector, I have always liked the rectangular ones. They direct more light downward, and work well over a 4' x 8' sized garden. In reality, as I mentioned before, the particular reflector style will only affect the usable light getting to your plants marginally (especially with my other suggestions in place).

You will want a reflective material on the walls of the grow room. There is a roll of thick plastic sheeting available from many hydroponic suppliers....it is black on one side and white on the other. It is highly reflective, and more affordable than mylar. The sheeting will catch any light leaving your garden (hitting the walls) and direct it back into the garden for the most efficient use of your light. It is yet another reason your choice of reflector is not as critical as the retailers would have you believe.

There are a couple of features you may want to consider when choosing a reflector. Mainly, these features are meant to make cooling your grow room a little easier. However, as far North as you are, you may decide you do not need any of the following features. One of these features is 6 inch vent holes (one in each end of the reflector), designed to allow 6 inch ducting for air cooling your light(s). Another feature is glass in the bottom....which would allow you to separate the air in your grow room from the air being used to cool your grow light(s).

Being in the far North, you may be able to get away without venting the lights at all. If the room does get too hot, you could always allow just a little cool air into the room from the outside. The daily temperature cycle in the grow room is a little bit of a balancing act that you will have to figure out once your lights are up and running.

It is interesting that you are planning to start with soil first, master it, then move to hydroponics. That is exactly what I did over the years. The following is just FYI from my own experience. Soil is more expensive than hydroponics by about 20% (the food is in the soil mix, instead of buying hydroponic nutrients). Soil is much harder to master than hydroponics (even though I was intimidated by it at first and therefore did not even attempt it for several years). Finally, soil is much more work than hydroponics. Every grow bag or container is watered on it's own schedule as it needs.

Furthermore, you end up mixing all of the nutrient solution by hand, and hand watering. This requires extra space, because every two or three days you have to pull every single plant out of the garden to check and water it. Working a garden in soil really is constant work. For a garden your size, I would guess two hours a day minimum. With hydroponics, you check and adjust one nutrient reservoir (takes about 5 minutes), and the hydroponic system feeds and waters every plant in the system 24 hours a day. The only other thing you have to do is change the nutrients every two (or three) weeks.

It is best to let water sit out overnight in a large plastic storage tote to allow it to de-chlorinate. Chlorine levels usually do not cause a problem, but they can....and sitting the water out also allows it to come to room temperature, making damage from temperature shocks a non-existent problem. I have seen a whole garden killed almost overnight because the guy used cold tap water for his water change.

You will be disappointed if you try to grow corn indoors, because of it's particular pollination requirements (which are practically impossible to provide for indoors).

Finally, ideas on having a 24 hour garden. There are some crops that produce edible parts in the vegetative stage (which would be 18-24 hours). These include spinach, all lettuce varieties, and many herbs. In addition, there are certain crop varieties that pay no attention at all to the daytime or nighttime photo period. These include ever bearing strawberries and day neutral onion varieties, you can probably find several other veggies. Honestly, I don't know for sure, because this is an area I have not researched well personally....but I think you may find it difficult to fill a whole garden of your size with these type of plants. One place that would know for sure are the scientists in Antarctica- I believe they try to grow only 24 hour crops, and there should be something on the internet about their garden.

The gardens that NASA grows in space might be another good lead for this kind of information. Finally, the Territorial Seed Catalog is packed full of information on hundreds of different varieties of everything you could ever want to eat....I tell everyone who gardens to order a copy and give it a read. If worse come to worse, you could always have a separate smaller area for salad greens and herbs (and possibly the next crop of flowering veggies while they grow in the vegetative stage). I hope this helps you out Dave, and Happy Growing!