I've been getting a lot
of Aquaponics questions both on and offline, so I thought I'd sum the
most common ones up in a single post. Questions have been paraphrased
to save space.
I'm very new to aquariums, so I was surprised to learn that a 10-gallon tank is actually too small for even a single goldfish. The aquaponics aspect also mean that you're better off raising tropical fish, since a heated tank makes the biology of the waste conversion work better.
To cut a long story short, we'll probably stock the tank with five guppies once the setup has cycled. Or possibly with some of AquaSprouts' other suggested ornamental combos: 8 neon tetras plus 4-6 dwarf corydoras catfish; 5 tiger barbs plus 2-4 kuhli loaches; or 5-7 zebra danios plus 2 dojo loaches. Nope, we won't be eating our teaspoon-sized fish.
The growing medium in a hydroponics or aquaponics system needs to be something inert that holds water between drenchings but doesn't disintegrate like soil would to fill the water below with gunk. In this case, we're using expanded clay aggregate --- an extremely light-weight, rock-like substance formed by baking clay at a high temperature. You'll soon see some rock wool enter the setup when I start my basil seeds since seedlings can't handle the large spaces between the clay pellets.
I consider our tank in the toy category rather than the tool category. It's 95% for prettiness and 5% for production of herbs, and I'm well aware I could get the same production results with less input of electricity by growing the plants in a pot on a shelf. But it'll be fun and educational to watch the ecosystem develop, and I figure that's worth a little electricity!
It actually did smell worse than I'd expected, but the odor disappeared within 24 hours. Perhaps that's a sign that my ecosystem is starting to work (although there's still no measurable presence of nitrite in the water). Stay tuned for more nitty-gritty details as the project progresses!