Is Aquaponics really the most economically way to grow anything ?

[GaryD]

Hi Arachdog,

If I recall what I was told correctly, it has to do with moulting......and it applies to all freshwater crayfish. I've emailed someone who know much more about crayfish than I do.....to seek confirmation.

Nope........I followed it up and it seems I must have dreamed it. It seems that the main requirement of crayfish when moulting is general hardness (GH) of the water.....so that the calcium required for the development of a new shell is available.

Kaduda.....some species of freshwater crayfish are said to cover quite large distances in a search for a better home.

Gary

[arachdog]

OK Gary well thanks for correcting that. Although I imagine its still pretty impractical to grow Marron in the bottom of a DWC tank. They may survive but I'm sure you would get terrible growth rates and rampant cannibalism. Also I should probably acknowledge that its not just DO that will drive them from their tank, any other water quality issue (or predators as you suggested) would have the same effect. Its just the DO that usually does it because the other parameter don't move around much in traditional pond culture.

[GaryD]

Hi,

As I said earlier, Macrobrachium rosenbergii......aka the giant river prawn.....seems like a better deal for those who can access them.

You can (and should) put air lines along your raft tanks......as much for the plants and bacteria as for any fish or prawns.

Gary

[CarolynAllen]

Very interesting insights into the sustainability issues and the costs of doing business. I see the need to localize a percentage of food production in urban areas as a major problem for the future as environmental problems increase, costs of transporation and fertilizers, etc., increase, and water becomes a scarce commodity. The benefits of a recirculating system is that is saves a high percentage of water use (I've heard up to 90%) which is essential in the parts of the world with fresh water problems (shortages and pollution). It is also an organic system, which has health values. And the ability to create significantly more pounds in the space of a garden makes it a viable urban agriculture asset. Am I overly optimistic about the benefits and future of this closed system that is basically a "biomimicry" approach to the natural cycle of plants and animals supporting one another?

[GaryD]

Hi Carolyn,

The benefits of a recirculating system is that is saves a high percentage of water use (I've heard up to 90%) which is essential in the parts of the world with fresh water problems (shortages and pollution).

When compared to commercial horticulture, or even traditional home gardening, recirculating aquaponics is efficient in its use of water. Non-recirculating (open loop) can be just as efficient if designed properly.

Of course, Aquaponics is not the only way that fish and plants can be integrated. Using the nutrient-rich water from non-aquaponic options like square foot gardening and wicking worm beds also allows for water efficiency to be leveraged.

Am I overly optimistic about the benefits and future of this closed system that is basically a "biomimicry" approach to the natural cycle of plants and animals supporting one another?

You're right. Aquaponics is bio-mimicry of a sort. It's origins are in the fish, duck and rice (and similar) integrations that have been used in Asian countries for centuries.

As you're aware, traditional mixed farming involving integrations like dairy cows, pigs and chickens persisted up until the advent of factory farming.

The New Alchemists (Drs John and Nancy Todd and William McLarney) are arguably the people most responsible for aquaponics as we currently know it. They experimented with integrations that included not only fish and plants but also ducks, worms and rabbits.

Aquaponics is a simple eco-system.

Gary

[Popparex]

This has been an interesting thread and i’m not so sure how i feel about it.

In regards to marron, i believe the largest drawbacks are water quality and slow growth rate. They happen to be particularly sensitive to water quality and i am not sure that aquaponics inherently lends itself to their needs. I have been playing with redclaws myself and other than concerns about temperature requirements I see some potential there.

I think at issue is more a sense of philosophy than it is of economics - much like “Organic” produce was before it became the darling of corporate agriculture. Can we leave less of an imprint on the world doing it this way? At some point, when the backyarders and small growers have figured it out - the conglomerates will embrace it.

[GaryD]

Hi Popparex,

At some point, when the backyarders and small growers have figured it out - the conglomerates will embrace it.

I think one of the things that many aquaponicists suffer from is the belief that there are things about growing fish or plants that have yet to be figured out. The reality is that the aquaculture and hydroponics/horticulture have most of it sorted already..... we're just slow to embrace some of the realities around that.

There will always be areas that are being researched and tweaked but the body of knowledge is largely there.

Gary

[SimpleMark]

Very interesting! Thank you to all the contributors!

[Damon]

when it comes to an energy input vs. energy out put, aquaponics hasn't been stretched to it's limits.

yes you do have the option in hydroponics to specifically tune your system to the needs of your crop, but aquaponics is more than just a nutrient value.

im assuming that with the hydroponic farm you're referring to is ever a natural spring. where Aquaponics reigns supreme is the fact that the recirculating systems are perfect for places dat arent located near a spring where water is free. with aquaponics a commercial system can be built next to the pyramids, in the goby desert, or on the mountain tops of peru. in some places water can be a very expensive commodity.

and yes, like i stated months and months ago, there is a defining line you have to cross when it comes to a system. you either fish or produce.

in a produce system, it has yet to be determined indefinitely how many fish will produce an adequate nutrient level in a well established system. like ive mentioned in other threads the FAP farm was running a system 3 times larger than the amount of fish were supposed to be supplying for. (based off of the UVI's math) this lead us to believe that not all system nutrition comes strictly from the fish food. im a firm believer that the microbiology of the system uses the suns input as a base for nutrient input as well as the fish food, but you'll only see this in a well established system.

FAP established one UVI system, then expanded the growing area every few months once the nutrient levels were even balanced and the ph remained securely in place. i don't think they ever added another set of growing troughs to that system, mainly because of the current financial troubles, but im willing to bet dollars to doughnuts that it could have been stretched to have a growing area 4 times the UVI recommended size. (with added aeration in the growing troughs of course.)

in summary, the absolute minimum fish mass to growing area ratio has yet to be found in an established system, and the key words being ESTABLISHED SYSTEM. THe running cost of that tripled system was only increased by the amount of electricity that was needed to aerate each addition set of growing troughs. same amount of fish, same amount of fish food, 3 times the growing area.

[GaryD]

I think we've only begun to scratch the surface of what is possible in terms of the production relationship between fish and plants.

There is more to the development of plant nutrients than what comes out of the fish.

If aquaponics is really about plants (in terms of commercial viability), then the current one-size-fits-all approach to nutrient production will have to become more about nutrient profiles tailored to specific plants, shrubs or trees.

And it's not just about the inorganic mineral content of the nutrient mix.....as is demonstrated by biodynamics or other organic growing methods.

External processing of the nutrients (to the aquaculture/aquaponics system) would enable the inclusion of organisms which are beneficial to the plants (probiotics).

Picture a scenario where the most profitable output of an aquaponics system is the production of plant tonics or elixirs for sale to other home gardeners.

Gary