|
Hi friends:
First, sorry about the multiplicity of posts; I am new to your forum and had no idea what the frequency of lookups really was. I wanted to get to know you by getting some replies and finding out what you guys (and ladies) are interested in. I don't really have much of a life except for the farm and my kids right now.
This is mostly a reply to RupertOfOz. I heard your questions about costs and so on, I just don't know where to start. When I sat down three months ago to write the course manual for our aquaponics training, it came out to 74 single-spaced pages. This did not include the sample business plan, the 27-page system construction manual, or the 2 sheets 24" x 36" of CAD drawings of the system. We added a couple of two-page addendums of stuff we learned during the course.
(Rupert's questions) what sort of vegetables are you growing?
There's a ton of stuff aquaponics systems grow really well: basil, thyme, oregano, cilantro, Italian parsley, and other specialty herbs; all kinds of lettuces, chives, green onions, leeks, green beans, purple beans, snap peas, regular peas, Japanese cucumbers, all kinds of tomatoes, many different kinds of oriental stir-fry vegetables including Kyono Mizuna, which sells for $12/lb around New Years, cabbages, kohlrabi, silver beet, Swiss chard, and broccoli. We forgot to try cauliflower but grew some later just fine. We grew some odd stuff like tomatilloes, garden berries, thornless blackberries and amaranth (a GRAIN); I am sure there is a lot of other stuff that would grow well, but we were primarily focusing on crops we thought had commercial potential. Strawberries grew really well until the Chinese beetles decimated them. You can keep them away with an intact greenhouse, or by low-wattage lights strung over them and turned on the first two hours of the night. The problem with the light system is that the beetles just go to your neighbor's place after initially getting attracted by the smell of your strawberries.
We had several varieties of tomatoes that did really well, but attracted insect pests like nobody's business. These would thrive in a greenhouse or screenhouse situation. We considered putting in a system just to grow tomatoes, and probably will when we have the money for the system and an extra $10-15,000 or so for the greenhouse. Tomatoes need some kind of support, and they put a LOT of weight on that support. Figure for just one raft of tomatoes, the plants and fruit can weigh two to three hundred pounds. Build your support structures accordingly, and build them so you can get your hands in there and harvest easily.
We grew watercress, pepper cress, and other cresses in the margins of our hydroponics troughs. It grew well just floating free, but if we were to grow it commercially we would need to figure out some kind of containment system that would also help in harvesting it, otherwise it will all mush up against one end of the trough when the wind blows. Also, it needs to be held so it shades the trough because if we get sunlight into the trough that will encourage algae and kill off the nitrifiers.
Flowers – edible and cut – grew beautifully. Leeks grew in half the time it takes to grow them in the dirt, and got HUGE, while still being quite tender and flavorful. We had to go to 3" net pots because the leeks were so huge they would rip chunks of raft out when we harvested them.
cost of seedlings?
What we are using now are sprouting starts in their plastic trays in what we call a sprouting table. This is a 4' wide, 24' long, 5-1/2" deep fiberglassed plywood trough on 3' legs that has 1" or so of aquaponics system nutrient water flowing from one end to another when a valve is opened for a half hour two times a day. This is what is called in hydroponics an "ebb and flow system". The nutrient water comes out of the aquaponics system, then goes through the sprouting tables, then through a drain back to the sump tank of the system, all by gravity flow. If we let the pots sit in standing water for long periods, the roots tended to rot and the starts died, so we instituted the ebb-and-flow protocol which works very well. The net pots cost us $0.02 each, the coconut fiber per pot about $0.005, and seeds about $5-10/5,000 depending on source.
sale price of produce?
Sorry, Rupert, the marketing and sales section of our training (for the vegetables alone) was five pages. Basically, we process our own farm's vegetables, package into labeled and heatsealed resealable biodegradable plastic bags, and sell wholesale for between $4.50-$8.00/lb. Remember, we're in Hawaii, everything is expensive here.
what sort of fish, cost of fingerlings, cost of feed, FCR, sale price of produce, "live" sale or chilled?
White tilapia (a cross between niloticus and mossambicus, we think), and a pure aureus line, about 2,000 lbs of each at the farm right now; we have our own hatchery and aquaponic nursery systems; fingerlings at survival age (2" long or bigger) cost us about $0.25 to get to that stage; cost of feed is $.75/lb and going up; FCR is 1.7 to 1.8; we get $5/lb at the farm for live fish as we have a large population of ethnic groups here that appreciate good tilapia. Frozen Chinese tilapia is $3/lb in the stores, and fresh local is $3-4/lb and often tastes like cow pond because the growers don't know about purging their fish. We sell almost everything live; haven't had to go off the farm yet to sell.
size of tanks and stocking densities?
Our basic system is on the UVI model and has: 2,700-gallon rearing tank, 560-gallon clarifier, 180-gallon mineralization tank, 120-gallon degas tank, and four 2,000-gallon hydroponics troughs each with eight 4' by 8' by 2" Dow Blue Board styrofoam rafts. Stocking density is 1,000-1,100 fish in the rearing tank averaging 1,200-1,500 lbs of biomass depending on where we are in the harvest cycle. We have 300 macrobrachium rosenbergii, Malaysian Tiger Prawns, in the hydroponics troughs under the rafts; just harvested some of the larger ones after three months in the troughs and they averaged 5 to 7 per pound with some in the 3-5/lb size range.
size of raft channels? 4' wide by 12" deep by 58' long, 4 raft channels per system.
flow rates, etc? Flow rate is 35-40 gpm, the blower for the whole system (with quite a bit extra pressure) is a Sweetwater S31 plumbed into 2" air distribution line and 22 Sweetwater AS15S airstones in the rearing tank, 4 in the degas tank.
|
Backyard Aquaponics
That's about the equivalent of 1kg fish per 8 litres.... only possible with Tilapia... not available or allowable here in Oz unfortunately....
