Aquaponics = sustainability?

[keen101 (Biolumo / Andrew B.)]

I saw a really cool video on youtube today. Thought i'd share it with everyone.

I think it's an awesome idea to use the nutrients from the fish to feed the plants, and the plants to clean the water for the fish. It eliminates the need to buy nutrients for the hydroponic system, and the need to get rid of the fish poop.

www.youtube.com/watch?v=DqS9ZXUPz2k

[synergy]

Silverseeds was talking about aquaculture the other night and then this post was the first I have seen on aquaponics and it was simply amazing to see so many examples on You tube. It really can be diverse in it's production . I have some personal idea of having a pond and channel system with subsequent small catchment pools on my sloping land , where buried under the pond is a geothermal heat system for my home heating and the pond itself serves for conserving water, moisture for other planted crop areas, animal habitat etc. I have never actually heard of anyone combining geothermal with a pond so i really have no idea how realistic and workable that is, I just thought it might be a good way to optimize use of the area the pond takes. Aquaponics too seems to optimize a permaculture type system .

[atash]

One problem with aquaponics is that relatively few people in North America, aside from Chinese immigrants, have much experience doing it. There was a fairly big project that failed due to the inexperience of the participants. They blamed the concept, but people in the Old World have kept fish as livestock for millenia now.

Another fairly serious problem is that the fish that works best, Tilapia, is tropical. It needs warm water and dies if the water temperature gets so much as tepid.

Ideally you want air-breathing herbivorous fish that do not eat their young. Tilapias, which come from brackish stagnant lakes in Africa, fit the bill.

The few coldwater fish that work are Chinese carp. Alas exactly what makes them suitable makes them banned probably throughout North America, except as artificially sterile triploid forms. The reason is that they can live on less food and oxygen than native fish, and quickly out-compete them.

You could use native freshwater fish, the problem being that as far as I know, most of the ones humans would be interested in are not herbivorous and get expensive to feed. Plus they eat each other including their own spawn, so you have to create situations that protect the eggs and young fish. Also, I don't know if any of them are air-breathers, so you have to aerate their tanks and/or ponds, or else keep only a small number of them relative to the size of the tank or pond. Otherwise, they suffocate. I've heard that catfish are feasible because they are relatively tolerant.

Not really fish, but Crayfish are supposed to be easy. I am not familiar with Crayfish biology but some types seem to be semi-amphibious and may wander in and out of their ponds. I've often wondered how much meat is on a Crayfish. I've never eaten one but my wife and daughter would.

I could not even legally keep Tilapia. My state has the most draconian ban on transport of ANY live fish although obviously enforcement is selective (Chinatown is full of tanks of live Tilapias, and I doubt they are all licensed and fees paid). It is not legal here to even stock your own lake with native fish, without a license and a permit. The state maintains a de facto monopoly over fisheries. An artificial backyard pond with no egress to other water is not exempted. Ostensibly the reason is "ecology", but the state stocks fish in alpine lakes that have no native fish, thereby wiping out the frogs.

[spacecase0]

I just remembered where I have seen Tilapia before,
someone at work had them
they are territorial and fight each other,
I watched 4 of them kill each other till there was only one left,
if you make lots of structures inside the tank, they will keep to a tiny section and tend not to fight as much,
very pretty as well

[atash]

they are territorial and fight each other,

Interesting. I looked it up, and it depends on what species. Some are solitary, and some swim in schools.

Also, apparently not all of them are herbivores.

And some aren't considered Tilapias anymore. The genus has been broken up. The fish I am thinking of are more likely Sarotherodon, but people still call them Tilapias.

[spacecase0]

I now have 6 koi
they are very cute
now I have to work out how to grow food for them

[synergy]

There you go, you're started already on replicating a natural balance between the fish, biological filtering and plant growth. They also get to be very friendly eating out of your hand.

[silverseeds]

The asian carps are not actually the best cold water fish for this. The reason being is that they are not easy to breed in a pond, or in tanks. The common carp though will do as well as tilapia in that. They were and are extensively used in this manner, but the eggs are wild collected its not easy to breed them in captivity, not for a back yard set up anyway. The large tilapia will eat their young just as any carp would. In tanks anyway. Either species yo must either just accept heavy looses, or have the babies in their own breeding tank, taking out the fathers after the eggs are fertilized, and the mother after shes done with her side. any one that can manage a tank or has a pond (i a warm area for tilapia) could breed either one easily.

There are several varieties of what are all essentially common carp. Koi mentioned above being one. Most of these selections are all fast growers, and eat a varied diet but the mirror carp out performs all of them. It is also essentially omnivorous, which is a major bonus. the reason being is you can feed it anything. insects, plants, sprouts, algaes you purposely bloom in your tanks or ponds.....

It also is a air breathing if it needs to be. It grows much larger then other types of common carp, nearly on par with the "asian" carp. It grows as fast or faster then asian carp. And the guy I got it from has grown 4-5 tilapias or rather has 4-5 types now, and these grow much faster then all of them.

It was bred/selected.... by monks in europe for fast growth, and less scales which is easier to harvest the fish.carps are still grown all over the world.....

ad actually atash there is a TON of info out there on this. you do though have to piece it together, if you want a totally low tech set up. and want to maximize production. but simply throwing pirror carp into any farm pond would be enough. Causing algae blooms will increase your fishes food. supplemental feeding does it again.... oxygenating allows them to grow bigger, and be healthier.... Meaning its a real easy animal to raise, at any level your able, in a pond..... In containers you have to do some things.....

If you have lots of water, it can simply be feeding them, and draining water each day, and adding more. If water is limited to get out nitrates, you can use filters easily for low concentrations of fish, unfortunately, filters that can take out nitrites for heavily stocked small tanks, dont seem to exist. they have such filters for large tanks. So for now im changing out the water..... A bio sand filter though will solve this problem. which I will be making soon. They have a much larger area for the bacteria that eat the nitrates to live, then you can easily get. It all depends on th concentrations of fish. and though tilapia and carp can handle high concentration of nitrates and nitrites its not something you really want anyway.

the issues with feeding plants with the fish waste water imo are there are a few things the fish water wont provide many plants. So its not a totally close system, and thats fine but to be mentioned. Plants will grow, but most wont be that productive without the outside inputs....

also if your trying to clean water for a large amount of fish, like enough to feed yourself, youd need a huge greenhouse full of plants. So its not real easy to set up a closed system if your growing a number of fish, and this is the only way you intend to clean the water.

a great way if you have a pond is to spread manure in the pond. Well aged manure. Like 18 inches or more thick. This will cause regular algae blooms throughout the year, and even without supplemental feeding will feed a good number of fish well. Sometime when its cold, you pull the manure for your gardens, its much more enriched then it was when you put it there, and put your new manure in the pond again, instead of the fields..... You can of course still supple mentally feed the fish.

Mirror carp is just a selection of the common carp, so most americans should be able to find it. Koi and other common carp have the same attributes but do not grow as fast, or as large. Also the mirror carp are more agreeable to a wide range of a diet.

[steev]

SpacecaseO: Koi are feral there in the Central Valley. I've seen them in Hatfield State Park, one a large golden beauty. In Applegate Park, in Merced, when the river was down to pools during drought years ago, there was a population of red and charcoal koi, at least a dozen. Pop claimed they were introduced by breeders using the minnows for bait and dumping the remainders at the end of the day.