DO I NEED A GREENHOUSE?
No, not necessarily. There are plenty of people with very successful aquaponic systems that are not contained within a greenhouse. However, constructing one–though initially time-consuming and costly–is not only a fantastic experience, but provides some tremendous benefits.
The most obvious benefit of building a greenhouse is that it acts as a natural barrier against pests and contaminants of all sorts. If you live an area with raccoons or hawks, for example, they will not hesitate to go after your fish. Caterpillars, slugs, aphids, etc. will find their way into your growbeds as quickly as possible. Such creatures can readily damage your fish stock and your plants–but only if they can reach them. Perhaps even more threatening than various animals and insects is the possibility of contamination. Dust, dirt, bird feces, falling leaves, and so many other things can find their way into your aquaponic system. Although such things may be harmless, they may also have serious consequences. Dust and dirt can create turbid, dark, and oxygen-poor water, as well as physically damage your plants. Bird feces can and other contaminants can drastically alter the delicate pH and nitrogen balance within your fish pond. Falling leaves can decay within your pond and lead to eutrophication. Airborne seedlings or seedlings contained within feces can even germinate in your growbeds and grow into unwanted weeds or pest plants. There are any number of ways your aquaponic system can be depleted or contaminated, but a greenhouse provides an ideal barrier against many of these threats.
It is not uncommon for people to say that building an aquaponic system in a garage or carport would be much easier. Although it is true such a system would not require the construction of a greenhouse, there would be so little natural light present that photosynthesis would be extremely diminished. Systems built in outdoor greenhouses receive abundant natural light, and materials like polycarbonate also perform the invaluable task of filtering harmful UV radiation. Moreover, an indoor system is not nearly as aesthetically fulfilling as one incorporated with the outdoors.
A greenhouse acts as more than a barrier against pests and contaminants, however. One of the greatest advantages of building a greenhouse is its moderation of such forces as wind, rain, and especially temperature. Severe winds can uproot crops. Heavy rains can drown the roots of your plants. Particularly high or low temperatures are incredibly dangerous, as slight variations can easily kill entire stocks of fish. A greenhouse, however, stops both wind and rain. In cold areas (like where I live) greenhouses do an outstanding job of keeping temperatures high, and on particularly warm days or in particularly warm areas passive solar vents and fans can prevent overheating while still guarding your plants and fish from pests and contaminants.
So no, you don’t need a greenhouse, but I highly recommend you consider constructing one. The process can be very simple or very complicated depending on the sophistication of your edifice, but no matter its complexity it will certainly make your aquaponic system more beautiful, enjoyable, protected, sustainable, and efficient.
WHERE TO BEGIN
There is no “one-size-fits-all” formula for constructing a successful aquaponic greenhouse. There are, however, a number of important things to consider before beginning the building process. Let me give you what I consider to be some good beginning steps:
- Design a frame. Decide what size you would like your greenhouse to be and which direction you would like it to face. Make sure you have a good, workable area planned out before you begin building. You should know exactly what you want to construct before you begin the physical process of construction.
- Consider important biotic and abiotic factors. Think about the climate of your area, and focus particularly on temperature. Think about the requirements of the fish and plants you would like to raise.
- Decide if you would like to build incorporated pond(s) and growbed(s) or simply build a greenhouse around a number of pre-made containers. If the latter, you may be able to purchase a greenhouse kit.
- If you are a beginner, do some reading about safe construction. If you live in an area prone to earthquakes, for example, you may need to take some extra precaution in cementing in posts or building a flexible framework. If you live in an area with heavy storms you should make sure your greenhouse won’t be blown away or torn apart under intense pressure.
- See Optimizing Your Greenhouse below. Though not all these components are necessary to build a successful greenhouse, you should definitely consider them before beginning construction. In certain locations they are crucial, and in other areas they are nonetheless beneficial.
There are hundreds of little tips I could give you about building a greenhouse. There are hundreds more a professional construction worker could give you. Ultimately, just be sure to consider the safety and effectiveness of your structure–for your fish and your plants and yourself. It’s better to invest a good amount of time planning than to begin building a structure and realize you made a mistake half-way through.
And also keep in mind that you do not need to build a professional-level greenhouse. No matter its sophistication, it will make your aquaponic system more educational, enjoyable, and effective. So have fun, be safe, and make your fish happy.