floridafishin wrote:
Just a thought. Even though the produce there is too cheap to bother competing with. It is a shame to see such a value adder go to waste. You could use it as partial payment to the workers. They complain less when they and their families are not hungry. Saving you even more on labor expenses. With the added benifit of them vetting sick less. Because of the nutrient density of the food you gave them. You could also just grow exotic greens that are not available in the market. Then you could get a price that was worth it to you. Or another option. Instead of wasting the acrage needed to filter enough water to support your entire proposed, fish load. Start with a RAS. Then sell the filtered waste as fertilizer to local farms. Just my 2 cents.
Yes, the plants will be used, just not a major commercial factor. At the moment some will be turned into fish food, and some will go to the workers.
Last year didn't work out with the Zika virus becoming a major problem and a few other issues. Right now we are looking at summer of 2018.
On to planning!
There are a few things I'm considering.
1, the people working the site are going to be relatively unskilled,
2, high-tech materials might be hard to come by, and
3, labor is cheap.
So right now I'm looking at doing a very modular design flood and drain made out of ferrocement. Cement and chicken wire are available pretty much everywhere. Flood & drain is very robust as long as there is sufficient grow bed media. And the modular design of creating multiple systems will limit any problems in one system from affecting others. If we lose one tank out of 50, it's not that big a deal.
I'm going to be building a test system in my backyard that is a circular tank 1 meter tall, 1 meter wide with a rectangular growbed 10 meter x 1 meter x 300 mm.
The tank will have an overflow at 8 cm below the top of the tank, which makes for a maximum volume of 540 L. The low-tide mark will be about 360 L when the bed is flooded. At the moment I'm thinking 15 minutes flood, 1 hour drain.
The grow bed will have a volume of 900 L. I think that will be plenty. I might even make it a little smaller depending on how much the water fluctuation is. I'll be using regular gravel due to sourcing concerns.
So then there is the question of stocking. I'm debating whether to build one system per batch of fish, so they come in as fingerlings and grow to plate size all in the same tank or to use a constant weight of fish system where we'd have to divide the population into 2 tanks every time there is 50% growth. Still undecided on that one.
But at harvest time, we'll be looking at ~70 500g fish per tank. This might go down if DO becomes an issue. I'll be putting in venturi drains, but I don't want to pump any air because of power concerns. Assuming the 70, that would become wholesale revenue of $280 in 6 months (or $560 annually) per tank.
At that scale, we'd need 178 tanks to hit $100k in revenue. That's a lot of systems, so I might scale the size up from my backyard test. Land is not a constraint though.
On the employee side, each tank will require feeding, monitoring water quality, fish size, vegetable growth, harvesting, etc. If it were me doing it, I'd figure 15 minutes per day on average for all that. To be conservative, let's say 30 minutes. So one person can operate 16 tanks per day. And that would mean we are looking at around 10 people on site to run the operation.
10 full time salaries in Ecuador is about $60k, so $100k revenue is in the ballpark of reasonable. Build costs should be amortized over several years. I know ferrocement can last decades, and the materials are pretty cheap although I don't have local prices yet. So the build cost shouldn't be too bad. At that point, operations expenses become fingerlings, feed, and power. Using the vegetative growth as part of the feed should cut down on that cost, but I don't know what the power situation is going to be yet. I'll be rotating timers so that not everything is on at once to reduce the load.
Well, that's where I am. Next up, building the test system in my backyard.
Backyard Aquaponics
