Backyard Aquaponics
A place to discuss aquaponics

Firstly this might not be the best place for this, but what the hey...

Secondly these are back of the Envelope caculations based on US averages, and stocking rates pulled from the BYAP sales portion of this site... And there are a whole heck of a lot of assumptions made here, and I round wrong (up or down in order to get an "average" high square footage). That means this is probably completely useless.

The US average meat consumption per person per year is 270ish lbs I'm gonna be generous and say 275 lbs or 175 kg. Of that about 60 lbs is beef, 55 lbs of pork, 80 lbs of chicken, 15 lbs of turkey, and 10 lbs of fish, and about 50 lbs of "other" (My guestimate is that the other is actually a combination of everything, since these are only averages, along with lamb, goat, etc... I actually threw other in there as my sources don't add up) anyway that's just background info...

BYAP "claims" (I know highly dependant) each grow bed can support up to 25 fish. For this I am assuming the fish are trout and they are grown out to 400g. From what I've read the average yield of fillets from trout is about 60ish%, so each fish yields about 240g of meat (right at 1/2 pound). So each grow bed should provide someone with about 12.5 lbs of fish meat per crop of fish...

For the trout feed caculations I'm using Dr. Barrows vegetarian formula found here: http://www.ars.usda.gov/Main/docs.htm?docid=21911 . The main ingredients of it are soy protein concentrate, corn protein concentrate, Wheat flour, and soybean meal. Trout has a feed to live weight conversion ratio of very close to 1:1. To simplify things I'm basing this on 100 lbs of fish (for now), so I'll need 100 lbs of feed. This means the percentage amounts of each ingredient translates directly into pounds needed for each.

Soy protein concentrate needs about 3 times the amount of raw soybeans (per weight) to make it.
23.64 lbs x 3 = ~71 lbs.
Soybean meal needs about 1.25 times its weight in soybeans to make it.
13.30 lbs X 2 = ~17 lbs
71+17 = 88lbs
using average US yields it takes about 16 sqft to grow 1 lb of soybeans
88 x 16 = 1408 sqft needed

Corn Protein concentrate needs about 10 times its weight in corn to make it.
17.54 x 10 = ~176 lbs
using the average US yields it takes about 5 sqft to grow 1 lb of corn
176 x 5 = 880 sqft needed

each pound of wheat creates about .85 pounds of flour.
15.22/.85 = ~18 lbs
Using average US yields it takes about 16 sqft to grow 1 lb of wheat
18 x 16 = 288 sq ft needed.

1408+880+288 = 2576 sqft (240 meters Square) are needed to grow the main ingredients of 100 lbs of Dr. Barrows vegetarian trout feed. In other words... basically 2576 sq ft per 60 lbs of fish meat or ~ 43sqft per pound or 240 meters square to 27 kg of fish meat or ~0.90 meter square for each kg of fish meat. Basically that works out to just over an acre of farm land needed to feed a family of 4 (not counting the grow beds needed to keep the fish water clean) the average US meat consumption if the only meat they ate was fish. That's a lot better than beef is, plus you get tons of veggies...

According to these back of the envelope calculations each person would eat 540 trout a year using my napkin calculations.

540 fish x 4 = 2160 fish for the whole family per year OR about 42 fish per week.

Trout take 6 months to mature.

This leads me to wondering how many fish you would actually need in order to harvest 42 a week? Troutman would probably know.

I like your thinking. Would it be possible to grow your own fish feed?

See also:

viewtopic.php?f=18&t=15424&p=375448&hilit=fish+meal#p375448

D-- this is a question I've pondered...
I wonder if a seed meal other than soy or corn would be a better choice.

I don't know if you ever heard this, but in vegan circles, the smaller the bean, the better the bean (nutrition wise); packed the same value, the extra size is just calorie -- starch and sugar.

In that case, a seed meal like alfalfa, cotton seed, or even lentil... would be more nutrient dense than would soy or corn. In addition... you are more likely to get GMO free seed that ISN"T soy or corn.

Something you're not calculating... and I thought that was part of the deal... would be a cyclical notion of using AP to actually grow the food, in the long run, eh? Which would say.. that this was leaning toward a commercial sized venture.

Since AP is capable of turning our a more 'square-foot dense' growth, might we be able to get a third, at minimum, more grain production? The nature of agribusiness, as it stands, are the acres and acres of monocultural production. With AP, one could avoid that... or not.

My own calculations were rather driven by personal consumption... I love coffee. But, I get it shipped from other continents. That is really stupid, in the sense of the 'carbon footprint' of my daily cup o' joe. I want to try to grow my own wheat... I figure, here, I should be able to manage four 'crops' a year, because our temps are mild... but here's the rub... acreage doesn't translate with AP directly. Floats may work for leafy crops, but I'd think that grain crops would need more sturdy substrate. If only because they're top-heavy.

Coffee trees, once mature, produce roughly a pound of coffee a year. I'm gonna need a big grove. I do roughly three pounds a month... or, get more... thrifty, with my daily brew.

Can we 'integrate' our grow patterns? If we go to a 'community based' grow: not that anyone gives up their backyard unit... but more that we spread to 'community based collectives' to do things like grain, fruit groves, etc. My city (North Las Vegas) has two parks with 'large water features' that currently (like TC's ) are a place for waterfowl, turtles... but don't house fish. With the addition of fish, the addition of sump tanks and extended grow beds, those park features could start producing pretty quick. Would they be 'safe' for actual AP? Since they are open, I have no idea what the substrate of the ponds are, etcc??? I have no idea. But as the 'trend' grows... I think we'll see more utilization of existing features.
O, at least we should.

The problem with that is making the protein concentrates. Industrially the oil is pressed out,and the meal dried and then the meal is defatted by washing in hexane (or other solvent), then dried, and then the carbohydrates are washed out, either by an alcohol wash, or water wash. While you could do all that at home... you really can't.

DEnd are you aware of any North American aquacultural/aquaponics producers who are utilising the omega 3 enriched GM canolas out of Western Canada?

The real issue is protein per acre, at least in regards to trout feed. As far as I know Soy is the best at that, hemp is up there as well but it doesn't produce quite as much protein per acre as soy.



Around here, aquaponics isn't really viable at wholesale prices (with a few exceptions), it would be beneficial for marketing a premium product however. While aquaponics is more productive than traditional agriculture, land and shipping costs are so low that it can't compete. AP is suited well for making unproductive land productive, ie roof tops, city lots, etc..., or for areas of the world where greenhouse food production is actually profitable, at least commercially.



Grain and legume production rates are mainly dependant on sunlight availability, at least for good fields. AP is not going to change monocropping. Modern farming equipment is what ultimately causes monocropping, to change that we either have to accept higher mechanized movement costs in our food prices, or invent small automated harvesting/planting/fertilizing equipment that is much cheaper.



For coffee I'd use media pots/beds. For the Average US consumer 16 trees should produce our coffee beans for the year. In your area that would mean about 1000 sqft of space would be needed, and you should be able to get at least 2 crops a year...



[Sen. Joe McCarthy] Sir, are you now or have you ever been a member of the Communist Party? [/Sen. Joe McCarthy]

The main problem with the collective idea is the relative mobility of our population (people move a lot), but it is certainly doable, and there are a few around.

The problem with water features is for fish production you really want to isolate the fish from fowl and mammals as they are a disease vector for fish. controlling these vectors is essential for keep dense populations healthy (even at low AP stocking densities it is still dense compared to nature).

I'm not. But I would be very suprised if most of them didn't use them (or at least consider using them), as ALA content is part of the reason for including plant oils in the diet. The main problem is that plant omega 3s are short chain Omega 3s (such as ALA). While they are good (as they compete with Omega 6s for conversion) they are poorly converted in our bodies (less than 5% in males, women convert a bit better than that). What our bodies really need is about 2 grams of combined EPA and DHA Omega 3 fatty acids (these are long chain Omega 3s) a day (at 3 grams or more a day there is an increased risk of bleeding). DHA is the form that our bodies use, EPA like ALA is mainly a precurssor to DHA though like ALA it is poorly converted. The unconverted EPA like ALA does have its own benefits, so it's good to have some floating around our bodies. Plants are a good source of ALA (and other short chain Omega 3s) however they provide no EPA or DHA. Sources for EPA and DHA are meat (in low levels), eggs (in increased amounts due to feed supplementation, if it's not supplemented there is still some there as DHA is necessary for eye and brain development, but it is in lower amounts), eyes, brains, cold water fatty fish, and algae. Algae are the only primary producers of EPA and DHA, and the only vegetarian source. I only know of one supplement source for Algae DHA and that is DHAgold, I do not know of any for EPA. That is really my main Concern with Dr. Barrows vegetarian Trout feed formula. DHAgold might provide EPA, but its levels are not advertised, so it is likely they are low.

1 Square metre for a single IBC system

These canolas are producing the DHA and EPA omega 3 FAs as they have genes spliced from omega 3 producing algaes. So they are producing oils similar to fish oils.

I just saw your thread LOL, and I'll comment there.

What about alternative high protein crops?
Mung Bean Sprouts
Duckweed
Pumpkin Seeds
Asparagus
Cauliflower
Peanuts
Almonds
Spinach
Broccoli
Quinoa

We put the soybean on top - what about other crops helping the soybean out with the protein part? I know some are slow growing but......