Backyard Aquaponics
A place to discuss aquaponics

Good luck on your trial system! I don't know the regulatory system on tilapia but if you can get them, it would be worth the phone call and any followup meetings to get permits/licenses. That way you could cycle between tilapia in summer and trout in winter! So weather it is successful as a busness or just a really big hobby that pays for it's self, have fun at it!

It is accepted that most "green leaf" vegies grow faster in floating raft ,, especially lettuce, basil etc. I read somewhere around 25-30 days to produce and full sized lettuce.

That's from seedling stock under optimum light, temperature and nutrient conditions Chappo...

You can add at least another 2-4 weeks to that if conditions aren't right... particularly in winter..

Basil in particular will struggle through winter without heating... indeed it's almost impossible to get seedling stock of basil until late August or mid September...

just returned from the UVI workshop in St Croix.... only one pump, and it seems to be their mantra... they also pay something link $0.44 Kw/hr... "appropriate technology"

they do have some serious biofiltering. Clarifiers, mineralization tanks and virtually all of the nitrification takes place on the undersides of the polystyrene rafts.

4 weeks to harvest... but 3 weeks additional before transplanting. will attach photos of the seedling sizes later.

caught a cold, feeling a bit under the weather but will add what i can about the set up later.

ask questions if you have any.

Viable commercial business? Not sure, you have to be able to grow a lot of fish, and i mean a lot every week to get into the supply chain. Selling retail to restaurants would require you to process the fish (big expense) and a lot of time driving around 15 fish every day (what high end restaurant would want to hold fish over a few days?)

peter

I thought in the vast majority of these systems that the money was in the plants not the fish.

Yep, the money is in the plants, the fish are a pleasant and tasty bonus which, all going well, should pay for the system operating costs even at low stocking densities.

All serious commercial hydroponic and aquaponic growers have a separate sprouting system for their seed stock for several reasons. The main growing areas are expensive to set up and operate, so it makes sense to have a sprouting area that can operate at 40+ times the density of the main growing area. This shortens the time the plants are growing in the main system by several weeks to months depending on time of year/plant species.

The other factor is that, with few exceptions, seeds will not sprout AND survive in net pots in rafts no matter how much DO is in the system. If they do sprout they eventually rot. This is solved by an ebb and flow sprouting area where the seeds/seedlings are wetted and allowed to breathe at various intervals. So this is where a thin gravel/coarse sand bed may be very useful using flood and drain. Plant seeds directly into the media and then transplant when ready. Or use rockwool plugs in trays to the same effect.

Another factor is that it is easier to control the smaller sprouting environment/area, adding heat, light, etcetera if required.

Dirt farmers use soil plugs to sprout and plant out too.

Starting seedlings elsewhere is the most efficient use of space for the grow out ponds- think of them as finishing ponds; we do the same with beef- they're placed in feedlots and pigs are placed in finishing pens- all roughly the same size and the same age and ready for slaughter at the same time. All are conveyor style systems that move different age groups along until you reach that final finished product.

Crisphead takes 36 days from planting the seed to harvest in a raft system. You can get 49 Harvests per Year (as averaged by UVI @ 148 crops in 3 years) on 72 rafts or 2,304 sq. ft. in their system-
12 days in the nursery and 24 days in the grow out ponds, staggered into quarters for weekly harvests and continous nutrient uptake, without spikes of too much or too little available nutrients. (To maximize space, these should be spaced once more within the grow out ponds but most don't because of the hassle of pulling rafts already in line and the time involved.)
Seedlings are spaced at 240 per 4x8 sheet and only the best are transplanted to the ponds.
Maximum grow out spacing is as follows for the following lettuce types-
Bib is grown at 88 plants per sheet
Crisphead at 60 plants per sheet
Romaine at 48 per sheet.

Doing the math-
60 plants x 72 rafts/ 4 rotations x 49 harvests = 52,920 heads of commercial lettuce per year- about 5% of a commercial lettuce crop of 1 million head. Increase system size 20 times to reach competitive goals- hence the reason for my system design. But imagine logistically harvesting that much lettuce and maintaining a system or systems that size.

Finished commercial size crisphead is 5.3 ounces per head and must be free of holes, pests and tip burn (very common in AP).
One finished raft of crisphead lettuce weighs nearly 20 lbs., without the water.

Bear in mind that the production figures quoted from the UVI system.... are a reflection of near optimum growing conditions due to their location and temperature....

Canberra is a totally different kettle of dispair and wild fluctuations...

The local weather will mean significant constraints in seedling raising... unless within a dedicated and controlled environment.... it is also very labour intensive... and IMO.... just not cost effective unless you're going to be turning over 250,000+ seedlings per year...

Secondly, while I'm sure you've looked at the relevant aquaculture and food authority licencing and regulations McFarm.... have you really costed out the initial setup, and ongoing compliance costs...

Just how do you intend to market your fish stock??... "live" trade to restaraunts... or processed fish products....???

If the latter... you're going to need a complete HACCP Plan... processing facilities with significant refrigeration... and cold transport facilities.... pest control... labour and training... and significant monitoring and data collection procedures... and none of that comes cheap

RupertofOz my climate attenuation strategy is in this thread already, but will no doubt change as I build the system.

As said earlier, I ain't interested in the fish. I like em, and fish will drive the system and feed me and family, but they are merely ornamental otherwise. Only if I decide to progress to the next level will I even bother with Aquaculture permits and compliance costs. But these costs are a "known" and can be incorporated into the feasibility study numbers which include extrapolations of the trial system.

Ditto council and DA's etcetera. All structures will be temporary and removable, so council can be kept at bay during the trial period and only becoming involved if we decide to go further.

In short I will be treating this as a domestic experiment from which we can deduce if a full on commercial development is warranted. I am not interested in the compliance issues atm - they are an easily quantifiable cost of doing business if and when we decide to proceed further down this path.

Ditto markets for products. In forty years of business I have never had a problem finding viable markets for anything I've decided to pursue - it is simply not an issue I can be bothered with at this stage. If and when the time comes, the solutions will be obvious - even for the fish. The veggies are all sold anyway, and I am already NSW "Food Safe" and ACT Dept. of Health compliant and QA certified with our Beef, Pork and Lamb eggs and honey which we sell direct.

Figured you were on top of things McFarm...

Mentioned the climate aspect.. because everyone likes to quote the UVI production figures... as an example of a sustainable model.... often forgetting entirely the climatic conditions that pervail in the Virgin Islands...

Interesting about the UVI numbers, friendlies were told by Dr Rakocy that due the 10 degree F ambient temp difference between Hawaii and the Virgin Is. to expect less fish production and greater plant production (Hawaii is cooler). This has proven to be the case. So the cooler temps favour plant growth (up to a point), and as we all know, plants will drive the economic success of any commercial AP system.

I am fairly confident that temperature abatement and proximity to a captive market will bear fruit (pun intended).

Ignore this, I am trying to post the site images. Why a bloody simple copy and paste procedure seems too hard for the system is beyond me. I hate computers, the commands are designed and implemented by idiots.

Dummy spit continues..............

OK, so it appears that I need to upload the images to a public accessible web server, sorry folks I can't be bothered with the double handling involved - so no photos.

Administrators I suggest you delete this thread, as it is now dead.

No need to upload photos to a public website McFarm...

Just do a "reply to post".... add any text you wish... then scroll down to the "Upload Attachment" section...

Browse to the area on your hard disk where the photos are located... select the photo... then select "Add the file"....

Repeat for extra photos... max of three per post...

If you want the photos to appear in order that you post them... position your cursor at the end of your text... or where ever you wish to place the photo... and select "place inline"...

Photos must be a max of 800x600 resolution... and no more than 256kb in size...

Thanks RupertofOz, I've had a post dummy spit photo trial, and it's in the one too many things to do basket - not too hard, just too damn fiddly.