August 24, 2010
New Aeroponics Station
A lot of people have come to know the word "hydroponic" these days. Some may have even heard the phrase "aeroponic", though that's certainly much rarer. When I tell people that I've developed a fascination for it, there are a few predictable responses:
- "So, what, are you growing weed in your basement now?"
- "Hey, have you ever been to Epcot?"
- "Dude, the cops are gonna be knockin' on your door soon..."
It's true, hydro/aeroponic gardening has become popular among potheads looking to grow their own. In fact, I've discovered that some of the best information online about hydro and aeroponics comes from various message forums dedicated to growing marijuana. Interestingly, the other popular place that people have heard about hydroponics from is Epcot, in Florida. Epcot and NASA have spent a lot of time together, researching and developing various hydro and aeroponics techniques. Visitors to Epcot invariably remember the gardens, and the restaurants that serve food grown in the gardens. NASA is interested in soil-free growing mediums which are much-better suited to the low/no-gravity environments.
That's right, two of the leading authorities on hydro/aeroponics are rocket scientists and potheads. Interestingly, the potheads seem to be much more adept at sharing their knowledge, and tend to use parts which are easier to find at your local hardware store. As to whether spending time lurking in their forums will get you on some federal watchlist, I couldn't say. But I've been researching there for years, and have flown several times during that time, so I don't think I'm on any watch-lists.
The third best authority are the various sites and stores which sell hydroponics supplies. These are many, and I will reference some at the end of this article. But before I do, some of you are still scratching your heads and wondering what exactly hydroponics and aeroponics are. Quite simply, both are growing methods which use a growing medium other than soil. The primary difference between the two is that hydroponics tends to have at least part of the growing medium submerged in nutrient-rich water, while aeroponics involves the plants being suspended so that the roots grow in open air, and are regularly sprayed with nutrient-rich water.
There are numerous specifics and nuances that one could get into when discussing soil-free gardening, and I will save the majority of those for another article. This article focuses on an aeroponics station that I have just finished building this very week. My primary interest in this growing medium involves tropical plants which are next to impossible to grow outside in northern Utah, where I live. Hydroponically, however, I can try to grow them inside where the temperature is more constant. My focuses right now are lemongrass and kafir lime trees, which I've had little luck with in my previous setups. I'm fairly confident with this setup, however. I present to you my new growing station:
The majority of the parts came from Lowes, but the tubs came from Ikea and the timers and grow cups came from various hydroponics suppliers. The lighting came from a seller on Amazon. The wire rack came from Lowes, and actually uses parts from two different racks. The poles that come with those racks actually come in two parts, and have a bolt that holds them together in the middle. I bought a second rack, and attached two half-legs to the back of the first rack, to hold up a shelf which also came from the second rack. The wheels were purchased separately. It's already been convenient having the mobility that this provides.
The red tubs and lids came from Ikea. The brand name on them is Trofast. The clay pellets (called hydroton) and 3-inch grow cups came from Salt Lake Plant and Hydro. I chose hydroton because it soaks up water, but also allows for aeration of the roots. Hopefully it also has enough space between the pellets for the sprays water to get directly to the plants themselves. The lids, conveniently enough, come with holes in the middle large enough to accomodate 1/2-inch threaded PVC pipe (from Lowes). You may notice that I tried to keep my plumbing modular; the pipes on top can be unscrewed from the tee on the side, which can in turn be unscrewed from the feed line going to the water pump. The pump is a 500 GPH (gallons per hour) model available at Lowes, and probably plenty of other stores which sell pond supplies.
Looking inside the tub, you see more 1/2-inch PVC leading to a tee that feeds two sprinkler nozzles. These are full-strength nozzles kids, the same kind used to water your lawn. A friend of mine that owns a lawn care service was shocked that a 500 GPH pump was able to drive four nozzles, but in my testing it proved to be plenty strong. You may also notice some black on the side of the lid; it's important to keep light out of anyplace that has water, because light encourages algea growth, which can grow on the roots and keep them from soaking up any nutrients. That being the case, I have sprayed tar on the bottoms of the lids (Isn't that amazing? Aerosol tar?) to keep light out. I'd originally purchased the tar for some yard work, and saw waterproofing planters as a suggested use.
Speaking of water, you do need to have a supply ready to be sent to the sprinklers. I have used a 16-gallon tub to hold the water. Two of the hoses that you see are for drainage from the growing buckets, and one is the feed line from the water pump. You might also notice what looks like a thin tube; that is actually the power cord for the pump. It is a fully-submersable pump, so that's normal. That also means that you need to keep the water line several inches above the pump, so that it doesn't go dry and burn out. With past gardens I've ended up refilling the reservoir about every 2 to 3 weeks. You may notice that there is no lid for my reservoir; I just haven't gotten around to cutting holes in one yet. That means that I also haven't added any nutrient to the water. I'll have to do both soon, before any plants really start producing.
This station lives in a basement, where natural light is in short supply. Artificial grow lights have been available for years, but have traditionally been expensive and power hungry, and run very hot. Luckily, LED-based grow lights have become available over the years, which are cheap, consume very little power, run cool, and seem to be very effective. Some, like the ones that I'm using, focus on the fact that plants react differently to various segments of the light spectrum. The fact that plants tend to be green tells us that they are reflecting, not absorbing green light; they just don't have much need for it. But red and blue have been shown to be very productive, and are what my particular light boxes use. The fan in the back is also important; I have actually had mushroom problems with past hydroponics gardens, which disappeared within a week of adding a fan to circulate air.
The last components are critical, and one of them is also the most expensive. I use a lighting timer to turn my grown lights on at 5am and off at 9pm. Plants need rest, just the same as you and me, and around 8 hours is apropriate for most of them. My timer was a little pricier because it came with more options that I don't use, but you can pick one up for around $5 to $10 at Lowes. You'll find them in the lighting section. These are generally meant to turn house lights on and off when you're on vacation, so that it looks like somebody is home. My other timer was ridiculously expensive; I stil have no idea why. It's a cycle timer, which I have set to turn the water pump on for 1 minute and then off for 4 minutes, in a cycle. The cheapest I could find it was $70, and that was on sale. My local hydro shop carries what seems to be the same model, for well over $100. I saved my pennies for a long time to buy those.
You may have noticed from my photos some very sad-looking lemongrass and some very dead-looking kafir lime seedlings. These are all transplants from previous setups, and while the lime may be a lost cause (time to order some more seeds and start over), the lemongrass still seems to be alive and making an effort. It already has roots hanging down into the growing chamber. Hopefully in a few weeks I'll be able to post photos with happier-looking plants.
For those interested, here are some links to some of the parts that I used. You should not consider this an endorsement of any kind, but merely a record of what I had.