by ifni
Additional thoughts – wicks versus pumps; aquaponics?
3:46 pm in Projects in Process, Seeking Advice by ifni
The other thing I’m considering is an aquaponics set up – using a fish tank as the reservoir. I’ve grown philodendrens out of my fishtanks in previous years, and it made a huge difference in terms of the clarity and quality of the water, the health of the fish, and of course the health of the plants. I’ve read extensively about aquaponics; but that technology is almost entirely in the realm of commercial, large scale productions, and there just isn’t much info available for at-home size applications, and even less for in-apartment (micro-sized!) applications.
The idea, of course, is that you’re growing fish protein to go with the vegetable products; you feed the fish, the fish feed the plants, the plants clean the water for the fish. The most generic of setups include a pump/lifter that takes soiled water (including solids) from the fish tank to a ‘settling tank’ where the large particle solids are settled out into a bacteria biofilter (usually a big tub of gravel or plastic particles; you need lots of irregular surface area for the bacteria to grow on); the bacteria turns the fish urea and waste solids into nitrogen-laden plant-friendly water; you run this through the plant’s hydroponic setup, and then back into the fish tank. The plants suck up all the nitrogen and minerals and turn it into yummy vegetables, and give the fish back nice clean water.
There’s several hang-ups when contemplating doing this in an apartment. A) What fish to grow? It’s easy to get ornamental fish, but you’re dealing there with a whole industry of ‘not for human consumption’ where the fish are raised in very unhealthy conditions. Food-quality fish are generally too large to put into an apartment sized aquarium – in California, that’s usually limited to no more than 24 gallons. One food fish can grow to 20 inches; so what, you’re going to grow one Tilapia? Just not very viable. B) Balance. If you’re going with fish you’re NOT going to eat, you’re still dealing with issues of how is that going to affect the plants? Are the fish going to put out enough biomass to actually keep the plants happy? Do the fish have anything you shouldn’t expose food plants to? How do you figure that out? In my experience with my very casual Philodendrons and guppies experiments a few years back, having plants growing out of the tank vastly increases the how large a population you can keep in the tank without running into toxicity problems with the water, because the more nitrogen in the water, the more the plants grow, the cleaner they make the water… it’s all a very nice self-regulating system – when kept simple enough. C) Construction. But that’s something we’re all dealing with for any of the windowfarms.
I’m just sort of blathering on here. I should actually do some more research – I haven’t looked at in-home aquaponics in a couple of years, maybe there’s been some developments. If anyone has any suggestions or comments about small fresh-water food fish, I’d be interested in hearing about it.
Check out Ken Rinaldo and Amy Young’s project, the Farm Fountain: http://farmfountain.com/index.html. They have some how-to pics. Their system used koi and tilapia to grow basil, I believe.
As far as doing it in an apartment sized windowfarm is concerned, that would be awesome!
Being a saltwater aquarium keeper, I have been very excited about seeing someone delve into aquaponics with this and have not had the bandwidth to take on the added level of complexity of symbiotic ecosystems yet.
If you are incorporating it into a windowfarm, I would start with non-fruiting plants until you understand the nutritive properties of the resulting water. I would still go for a big tank too just because small tanks are less dilute and therefore can become contaminated more easily if you get one element of your system out of whack.
Please report back!!
That is an awesome project, and glad that they got to redesign it for a public art display. It’s awfully pretty!
I note that they went with a 100 gallon tank for the in-studio one and a 250 gallon tank for the museum piece – both too large for me to do in my apartment.
I think I’ll start the design process this weekend. This build is going to take months, just because the parts are going to be a one-a-month buy for me – aquariums are expensive to setup! At least that will give me plenty of time to start saving up 2-liter bottles >.< Maybe I’ll make this my first Instructable, too… hmm.
I’ve tried to build a small scale aquaponic system and I ran into a couple problems. First you need to take the chlorine out of your water or your fish will die like what happened to me, second doing it with edible fish and growing a decent amount of produce requires more space than your average apartment has. Third in order for the fish waste to turn into fertilizer it has to be metabolized by bacteria, and fourth salmonella and other nasties are a common problem in aquaponics so be careful. In theory it sounds great but I gave up after most of my fish ended up dying and put the survivors in the pond. Also you need to feed the fish and their waste doesn’t provide everything that all plants need so you need to also figure out how to supplement your plants with the rest of the nutrients without introducing those nutrients to your fish and potentially killing them, or stick to leafy greens and more nitrogen loving plants.
I just posted my home fish tank aquaponic set up. When selecting fish you have to take into consideration a few things…Will your fish eat plants(gold fish do), what pH do both the plant and fish want, along with the salinity and temperature. I found that the mollies I have been using are working great so far. The typical rule for aquaponics is one inch of fish for every gallon of water. This is supposedly the magic ratio for proper fertilization for your plants. I’m new to this but I have an aquaponic expert to consult if you have any specific questions!
Wow, neat idea! I used to work in the aquarium trade and I’m wracking my brain to find issues with the resevoir idea. In theory it should be completely possible. I’ve seen filtration systems that use mangrove to filter but that only works on brackish/salt water. From what I understand, ‘plant teas’ make water more acidic and most freshwater fish we keep are soft/acidic water loving fish which gives us an added bonus. As to some of the issues other people have cited I wouldn’t worry too much about salmonella, I siphoned tanks for years (read “I’ve swallowed an awful lot of fish poop laden water”) and never got sick, and chlorine disappears after 24 hours (it’s the newer chloramines that don’t).
In terms of filtration we have two stages, mechanical and chemical. By running it through a canister filter with only a sponge (mechanical) we hold back the solids but keep the nitrogenic impurities which are dealt with by beneficial bacteria growing on the compressed clay medium in the planters instead of ‘in-canister’ filtration balls (chemical), right?
You would seed the tank with bacteria and leave it running with no fish for two weeks before any introduction, wouldn’t use the water for watering as it goes through a nitrogen spike before it settles, and even then you would be talking about getting up to capacity over a few months. If you did use fertilizers you would have to use specialty aquatic fertilizers meant for aquariums or you would get horrendous algae problems and, literally, burn your fish out of their skins.
It’s do-able but I don’t think it would be worth doing with anything under 60 gallons, preferably 100.
In terms of fish you could use other cichlids besides tilapia like the Africans from Malawi or Tanganyika, all of which are edible, very delicious, breed rapidly and are farmed rather than imported from the wild. I’ve seen a ‘table tank’ that had snakeheads in it with a single head of lettuce growing out the top from two guys in New York but it looked more like a staging to me and full sized fish like that are more expensive than buying it at the market. Perch, bass and sunfish should also be possible if you could catch small ones locally form a lake. My favourites would be red-tailed catfish and pangasius catfish (aka Basa); both are fast growing, greedy, cheap as babies and would be ideal for producing large amounts of nitrates at the same time. Pangasius would be the better of the two as they feed on vegetable pellets and have an exceptional taste vs. the red-tail which is a little too smart and personable for a food fish that you’re going to have to smack over the head eventually (I’ve taught them tricks -seriously!). My other problem is that it would just plain cost too much to raise three or four fish to a suitable size to eat with all the cost of food and water treatments. It’s a nice idea but I think you’re better off supporting your local fishmonger unless you follow the wild fish route.
Here is my first attempt at close looped aquaponics. It has been running for a few days with some test plants in it. So Far So Good
http://nutsedgefarm.blogspot.com/2010/03/aquaponics-experimentation.html
What about using othe aquatic cratures in a small tank, shrimp? crawfish? snails? what are sources and edible types?
Also – I have seen a system that just had house plants, but it went like a bench around the walls of the rooms in a house, water flowing over the plant roots and the plants purifying gray water…a variation might be like that and might give enough room for fish to grow…probably not practical for a small apartment…