Why Aquaponics? Well, for starters, I wanted to get back into fish keeping and see if I could grow some salad greens in our cool temperature (50-60 degree F.) office. Usually we plant our garden outside in May, but I wanted to get a head start on the growing season. Call it cabin fever.
My system:
In January, I built these two "T barrel" systems in front of two west facing windows. Here is the design plan I followed: T barrel design
I planted salad mix and cilantro in the top 1/2 barrel grow beds. I started them in soil, and transplanted them once the shoots grew their second set of leaves, or "node".
In the barrel on the left I experimented with fathead minnows and in the right barrel I used golden shiners. The 2-3" golden shiners did much better than the much 1-2" fatheads. Besides their larger size, the shiners are top water swimmers. The fatheads are bottom swimmers, and used to much less current. They kept getting sucked into the water pump inlet.
I started with one light fixture over each barrel. These are 48" florescent ballast with two 32 watt 4100K tubes. I've recently doubled the number of ballasts and have swapped the 4100K "cool blue" tubes with 6500K full spectrum ones for better leafing growth.
I'm using 130 pounds of expanded shale in each grow bed. I wanted to use hydroton (expanded clay) because it's more porous and lightweight. But, this product is much cheaper, and supposedly chemically inert. I bought 4 bags of this product from Green Mountain Hydroponic & Organic Gardening Supply:
expanded shale
One of the most time intensive part of getting the systems up and running was cleaning the gravel.Since the shale is kiln fired, it has to be thoroughly rinsed or the dust will clog the fish gills and kill them.
I bought three 16 watt PonicsPumps (one as a backup) from Amazon, and chose this model:
water pump
I chose a flood and drain design and created a bell siphon in the middle of the barrels. This system automatically flushes approximately every 10-15 minutes, depending on flow rate. The flood and drain design was attractive to me as I had no plumbing experience but was inspired by the "Affnan Valve", by Affnan in Malaysia. Besides Travis Hughey, Affnan is another do-it-yourself aquaponic guru.
Here's his terrific blog with step by step instructions:
Affnan's blog
The initial investment of everything totaled about $300, about $100 higher than it could have been if I'd used free gravel from a riverbed.
What about heating and electricity use?
Cultivating a cold water fish, I save money by not needing an additional water heater in the tanks. During the day, the overhead lights provide a little additional heat to the plants, which in turn heat the water.
My current aquaponic electrical use:
256watts (for 8 x 32watt bulbs which operate 16 hours/day)
+ 32 watts (for 2 x 16watt submersible water pumps, continual use)
________
= 286 watts during the day (and 32 watts at night)
In late spring, I should be able to move my systems outside and grow in direct sunlight, but for growing indoors, supplemental lighting is necessary.
Once I got the system running, I just had to wait and see if the greens would grow.
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