Backyard Aquaponics
A place to discuss aquaponics

Thank you Andrew for coming on the forum. It seems that most people whos statements are questioned on this forum spend more time going to their lawyers than coming on here and putting their side so people can make an informed decision.

Any regular reader of this forum will realise there is a wide spread belief that the commercial aspect of AQ is much over hyped in Australia (and around the world) so there is a lot of scepticisim when somebody gets headlines in the news. Rupert generaly at the head of the queue. Rupert though (and most of the regulars on this forum) does have an open mind and will admit when somebodys arguments are proven more logical and factual than his own.

I for one am interested in further information on your project here and hope that this was not just a one off post.

I certainly think the current portrayal of commercial aquaponics is over hyped Jeff... in the form that it has been presented in... and the methodologies employed...

AQ... aquaculture is a totally different subject.... and entirely commerically viable.... as is hydroponic production...

Part of my concern as to the hype surrounding commercial AP... particularly in the US... is the fact that the models aren't predicated on the optimisation of the aquaculture component....

In fact most aren't even designed by aquacultural specialists... or based on proven RAS designs...or by people with any real aquacultural knowledge...

They're designed by backyarders... extrapolating backyard aquaponic concepts.... most with very little aquaculture experience or knowledge (if any)... and many pushing the hype... without even any commercial growing experience..

Indeed... many of the models... are either based on very low density stocking... or don't even sell their fish.. or the fish have no real commercial value....

My other perspective comes from my hydroponics experience.... and questions of scale of operation, and sale of product model....

From that perspective... the single, or two person operation... with a direct marketing approach... is limited to a certain scale... that IMO... is not really commercially profitable... especially in terms of a return on investment... and particularly without a profitable aquaculture component....

It's difficult to judge the real commercial potential of aquaponics.. when it's based on flawed design.. or business practice.... use of interns, volunteer labour, funny tax structures, not-for-profit models etc...

In Australia... we have potentially/comparatively high possible returns on the aquaculture component of an integrated system..... if it's structured as essentially a properly designed RAS component...

And the plant production component is similarly optimised... with controlled nutrient inputs...

And I have no doubt... that the RAS component of the system which is the subject of this thread... has been designed accordingly....and Andrews description of the gear supplied supports this...

Nor do I question Andrews aquaculture experience.. or ability to design a RAS system....

But I do have... both from my hydroponics experience... and from some knowledge of RAS... some doubts as to whether the scale is such that the project is truely "commercial"....

Likewise... it's always difficult to determine the true "commercial" profitability.... when infrastructure funding is by grants....

I do believe that intergrated aquaculture has a future here in Australia... and i do believe that that future will become apparant in the next few years...

And when it does... it will make the hobby farms of the US "farming revolution".... look like the hobby farms.. they really are....

Hydroponics went through the same things decades ago.... and for a while... there were quite a lot of single/two person operations.... but they were limited in scale... and ultimately unprofitable in terms of the time invested by the owners.. usualy for little personal return...

I know... I ran one...

For all the scorn that some people might throw at me.... I've yet to see anyone actually address... or debate... the questions I raise about scale... direct marketing vs wholesale price models... cost of labour etc...

You'd think that if I was so wrong... someone would just post the figures... and prove me wrong...

And I'd be happy if they did so...

To answer your questions in brief, the official opening was in November after visitation by the Governor of SA and his wife Mrs Scarce and the cutting of the ribbon a few days later by the Mayor etc.

The first group of trainees went through in May until June where they then all took off to do farming duties as blockies etc and some either started their own systems or visited where they could. The full planting wasn't until June/July and with a few teething problems sorted was producing around 300 lettuce on the winter 6 week cycle. As we don't heat water the ambient air temperature was 2-3 degrees with the water temperature lowest on the frost days to 8 degrees. Once full production is available after 2013 June then 600 - 1000 lettuce alone should be turned out depending on the season. Produce is sold to the IGA in the region, pubs/ clubs and a wholesaler down in Adelaide for a variety of produce. Basil is bunched as is coriander etc but although this is more profitable...is more time consuming and adds to the 1/2 hr per day maintenance. If we were to do just basil, that would equate to around 1000 bunches a week on the static holding capacity at the time.

I always oversize bio-filtration, first because this is pure NFT and there is only static solids filtration and not aquaculture duty feed inputs required ( ie 130 kg per day etc), secondly it acts as a buffer for oopsies similar to having excess water in a deep flow raft system and third it allows the farmer to run higher densities of fish if required to increase the nutrient flow for AP ( utilizing trout) during winter as bio filtration becomes more dormant or to add further tanks on scale up as may be required. Therefore, 4 tanks at 2000L per tank, 3 at 125 kg per tank and allowing up to 50kg for the fourth for fingerlings without pure o2. With pure o2 this can be doubled but the de-gasser must be run 24/7 but negatively does have a cooling effect on the water.

so you understand bio-filtration better:


A simple formulation is as such:

Assume that for each tonne of stock at a mean average of 700g that you intend holding and feeding at 1% body weight, 384g of Total Ammonia will be produced each day.

Viz. 1 kg of feed produces 38.4g of ammonia using the formula below.
10kg x 38.4g ammonia = 384 grams

Ammonia-nitrogen (g/kg feed) = (1.0 - NPU) (protein / 6.25) (1000)

Where

NPU = net protein utilisation
Protein = decimal fraction of protein in feed
6.25 = average ratio of protein to nitrogen

Values of net protein utilisation often are about 0.4 for high quality diets. Thus, for a feed with a crude protein content of approximately 40 percent such as that utilised in Murray cod feeds, the ammonia-nitrogen excreted would be:

Ammonia-nitrogen (g/kg feed) = (1.0 - .4) (.40 / 6.25) (1000) = 38.4 g N/kg feed.

Having calculated the Ammonia produced per day we can now calculate media requirement to comfortably maintain assimilation of ammonia at this level.

For each gram of Ammonia 1.6 square meters of surface area is required in fresh water.

Therefore, in a system designed to hold 1 tonne of fish biomass in fresh water the calculations are as follows:-

1 tonne of fish fed 10 kg of feed a day =
1 x 384g = 384g of ammonia/day.
384g x 1.6 = 614.4m2 of surface area needed.


Using gravel that has a surface area of 150 m2 /m3 you would need:-
614.4m2 / 150 m2 = 12.28 m3 of gravel

Using bio-balls that has a surface area of 400 m2 /m3 you would need:-
614.4m2 / 400 m2 = 1.53 m3 of bio-balls

Using Bead filtration that has a surface area of 1400 m2 /m3 you would need:-
614.4m2 / 1400 m2 = 0.4388 m3 of beads

Therefore to hold 400Kg of fish using gravel only would require:-

12.28 m3 x 0.4 tonne fish = 4.9 m3 of gravel
Average bed depth 300mm therefore:-
4.9 m3 x 3.3 =16.17 m2 of bed

Allowing a buffer of combined filtration of 1.53 m3 of bio balls and 8.64 m2 of expanded clay at 300mm deep (double that of the gravel surface area) will allow a total static crop of 700kg of fish.

Allowing that the standing crop will be 400kg at any one time and that fish will be grown to around 700gms plus and fed at a body weight ratio of around 1% per day at this size, this then equates to around 280 fish fed 4 kg of feed per day. Based on approximate ratios of known formula as per above for protein and protein to plant ratios, 35 - 45gms of high protein feed is required per square metre of vegetable production in media bed systems and up to 6 times this value capacity in NFT systems, therefore, 52 – 120 lettuce (size dependant) or approximately 135 multi-seeded bunches of herbs can be grown using 45gms of a high NPU feed.

400 kg of fish would therefore support approximately up to 4,576 lettuces only or 11,880 mixed herbs of varying stages of growth.

When the commercial proof of concept project finishes I am sure Canberra will have reports available.

Apologies for a miscalculation on my part...

should read

Using gravel that has a surface area of 150 m2 /m3 you would need:-
614.4m2 / 150 m2 = 4.096 m3 of gravel

and


should read

4.096 m3 x 0.4 tonne fish = 1.6384 m3 of gravel
Average bed depth 300mm therefore:-
1.6384 m3 x 3.3 =5.406 m2 of bed

Ammonia assimilation only and at optimal 28-30 degrees C

Indeed... many of the models... are either based on very low density stocking... or don't even sell their fish.. or the fish have no real commercial value....

Based on Johns comment...this is true, you do not need a large amount of fish to produce horticulture to a profitable quantity. If your output minus all costs including labor etc is less than the gross $ input of revenue from horticulture sales then nobody ever went broke making a profit hence, as business pays tax on profit, this is deemed a commercial enterprise. The Loxton facility is based on this being a commercial nursery for industry scale up and as a proof of concept for the area hence why we only used the 2000 L tanks and not 5,000 or 10,000 L tanks. Wilson used 2000 L tanks in his own small scale commercial system in King Lake and as such was limited to only 500 kg also of grown out fish production but nevertheless could still turn off 3000 bunches a week of herbs. Commercial aquaponics will not reach commercial aquaculture output densities simply because:

A) The market cannot sustain it and;

B) Based on the previous calculations I posted, a 135 kg input of feed per day for a barra farm only producing 100 tonne plus a year would equal around 157, 872 lettuce alone which would cover roughly 3.5 acres in NFT production. Or to put that into perspective, 27 million bunches of basil a year. The average person can not do this as they are not farmers of both degrees and only corporate enterprise once again will take this to these levels. Bobs Farm sector, NSW is one of these that tried although, it was built as a a flow through end of pipe NFT system not recirc. The point is, it was built by a consortium of 12 people not an individual entity. The whole agriculture industry will not change its whole perspective of traditional farming practice so there will always only be a majority small and mid sized aquaponic ventures only making small profit but nevertheless, commercial. To make greater profit from a smaller footprint requires higher skill sets in production diversity hence, full integrated farming systems not just aquaponics based; this is the true holistic approach to commercial, small scale production.

A great example of the wrong type of aquaponic diversification is as in the US where most profit comes from so called instant gurus books, dvd and training more so than weekly fish and vege produce itself and these business people simply are making quick money from a new unsuspecting buzzworthy sector. I saw this in the late 80s and 90s with aquaculture and again now in aquaponics. An example is with our own Aquaorganic registered trademark for services from 1aquaponics.com.au which includes systems, consulting, feeds and nutrient water based systems. This is well documented and seen on both you tube and our websites yet amazingly, one of a Murray Hallams well known colleagues in the US now sells their new developed aquaponic feed called ... Aquaorganic fish feed. Interesting how people just claim things as their own to make a quick fast buck hoping they can get away with it for as long as possible. I would like these hundreds of aquaponic start ups to actually give thanks to the 100s of researchers who went before them with blood and sweat and actually developed the know how for where they are now making quick money from. What would be a real act of honor is they actually admit they know very little about the science and industry itself or that they would actually do something constructive and work with governing agencies to truly develop a real industry sector with best practice for commercialization as previously cited. Develop EPA guidelines, codes of practice, recognised certified modules etc etc. If not, then say they are really novices on their websites not industry leaders and work in the backyard sector and also work with colleagues in their region/sector and help people put bio secure healthy food back on their plate in their backyard. I have seen too many people take credit for what they do not have a right to and colleagues like Jim Rakocy, Nick Savidov or even Australian Wilson Lennard have not been given the respect of making true commercial headway because of discredit to industry from shysters.

Anyway, this is not a vent and is not my norm but simply put as a comment as to why commercial aquaponics is in its state of commercial polarisation and believe me, I have seen it all since 1996.

Thank you for your post... your figures and details Andrew...

It's nice to see someone else basically on the same page.... for the same reasons...

At least you wont get banned here for saying such things... based on my eperiences... you wouldn't last long on a couple of other forums... expressing thoughts like that....