Not Quite Free
One of those great words I hear often associated with backyard aquaponics gardening is “free”. Most of the time, they mean “free as in beer” (1, see Linkliography below). In practice, it’s more like “free as in speech” (1).
Let’s take a look at a simple “Mark II” conceptualization of my basement aquaponics, including the lessons I’ve learned so far.
208 L / 50 US Gal Food-safe ABS "blue" barrels - $50 each. Need 2; total $100. ... cut one in half lengthwise. These are your growbeds. ... cut one 1/3 / 2/3 across it's diameter. The 1/3 is your sump, the 2/3 is your fish tank. ... Working water volume = 139L / 34 US Gal.
Lumber: 22 m / 75 ft of 50mm x 150mm / 2" x 6" framing lumber. Use to build shelving / supports. Use "glue and screw" for construction. Total $70. ... sump on bottom shelf ... fish tank on middle shelf ... grow beds on top shelf
Bell / Auto-siphon plumbing(2): Uniseal for 25mm / 1 inch pipe; 3 pieces of 25mm / 1 inch pipe; a 37mm / 1.5 inch to 25mm / 1 inch reducer; a 50mm / 2 inch piece of pipe; a 75mm / 3 inch piece of pipe; 3 25mm / 1 inch pipe elbows. Sub-total $25 per siphon. Need 2 (1 per growbed); total $50. ... assemble, install into floor of each grow bed. ... ensure outflow pipes pour into fish tank
Level drain plumbing: Uniseal for 50mm / 2 inch pipe; a 50mm / 2 inch piece of pipe. Sub-total $10 per level drain. Need 1; total $10. ... install in floor of fish tank ... ensure you leave 75mm / 3 inch clearance between top of level drain and top of fish tank ... ensure outflow pours into sump
30 Kg / 66 lbs bags of 6 mm / 1/4 inch gravel - $7 each. Need 6; $42. ... rinse the gravel well. ... add gravel to grow beds.
190 L / 50 US Gal per hour pond pump. $20 each. Need 1; $20. ... add to sump, away from level drain outfall
Non-kink pond tubing, 4.5 m / 15 foot length. $20 each. Need 1; $20. ... run from pump up to each grow bed
Lighting: 13W LED flood lights. $35 each. Need 6 (3 per grow bed); total $210.
There you go. Before fish and plants, you’re looking at about $500. That is not “free as in beer”. 25 small starter plants from your local commercial greenhouse might set you back another $50 to $100. The fish, depending what you get will go between $20 and $200.
On the other hand, a square meter / square yard of growing area with the right mixture of greens, strawberries, beans, peas and the like will potentially allow you to pull an organic salad for four out of this every week, year round. That’s around $10 value a week; that’s around $500 a year.
Return on investment: about 1 year, if everything goes well.
Along the way, you should do what you can to add to the knowledge base of the aquaponics gardening community(3). A blog, community forums, YouTube posts, even coffee-shop meets with folks in your local area. The more we all share, the better we all do.
So, no, this isn’t free. But it’s not expensive, either.
That’s it for this article! As always, comments and suggestions are welcome!