Is Aquaponics really the most economically way to grow anything ?

[arachdog]

Don't get me wrong, I love the idea of aquaponics in terms of sustainability and I think it works well as backyard food production method. However I've got this niggling feeling that compromises made during the merging of hydroponics and aquaculture have actually produced a overall system that can't really compete in either field.

Now I'll attempt to explain why I'm starting to feel this way. Firstly the main product from aquaponics comes from the growbeds. I'm sure it varies from system to system but the figures I've seen put the income split at 80% from selling the fruits and\or vegetables, and only 20% from the fish. So really what you have is predominately hydroponic system, but is it efficient one ?. Fish food is expensive, nutrients however are dirt cheap, so even taking into account that the fish food also gives you an extra product does it really turn out to be more cost effective ?

Then even if you answered yes to that question there's the bigger problem. Fish effluent is never going to be as productive as hydroponic solution specifically engineered for your chosen crop. Now I honestly don't know how close you can get to the perfect solution, But lets say you could achieve 70%. Now even if your hydroponic nutrients cost the same as the fish food (it doesn't) it terms of overall profit, your still better of using it.

To give you an idea of how cheap nutrients really are, take a look at the biggest hydroponic installation in the world, Eurofresh Farms. They actually use a Run To Waste system, that means the nutrients only get a single pass through the media before being discarded. So even though the solution probably contains at least 90% of its nutrients still after one pass the extra productivity you get from using brand new solution actually justifies the cost.

So in the hydroponic field it doesn't seem to be a winner to me. But what if your already growing the fish, is it worth adding a hydroponic component to diversify you income stream? If you could do it for free, sure. But it reality your talking significant extra infrastructure and land costs. Then once you've shelled out for an expensive array of growbeds. You look at it and say "Well there's a lot of money tied up here, I can't really afford to run this thing at 70% capacity, I better get in some proper nutrients."

[bunya boy]

If you are so worried about it... don't do it!!

[arachdog]

If you are so worried about it... don't do it!!

Well I don't intend to bb, not on a commercial scale. Unless of course someone can point out an obvious flaw in my logic. Which to be honest I hope they can because as I said, I do like the concept as it has potential to be more environmentally responsible (although high protein fish feed is still typically composed of some percentage of over exploited 'trash' fish, ie.anything they can catch easy and can't sell anywhere else).

Also let me be clear, on a backyard scale I think it works great. You getting fresh fish and veges that you otherwise have to pay retail for, so that gives you one over the commercial grower who only gets wholesale. You also don't have to start your car and go to the shops every week. It's easier to maintain than a hydroponics setup. You don't have to keep buying nutrients. All these advantages swamp the fact that its not the most efficient use of your resources. Not so for the commercial grower.

[GaryD]

Hi Arachdog,

To give you an idea of how cheap nutrients really are, take a look at the biggest hydroponic installation in the world, Eurofresh Farms. They actually use a Run To Waste system, that means the nutrients only get a single pass through the media before being discarded. So even though the solution probably contains at least 90% of its nutrients still after one pass the extra productivity you get from using brand new solution actually justifies the cost.

Run to waste doesn't mean that they dump all of the solution after a single pass. In fact, a correctly tuned run to waste system will actually waste very little nutrient solution.....and, even then, the bit that is drained off at the end will often be directed to other plants.

Non-recirculating hydroponics systems are very common.....and they have a role to play in aquaponics, too......particularly with growing media that holds water very well......like vermiculite and coco coir. Tailormade Farms is/was Australia's largest commercial aquaponics farm and it ran a non-recirculating NFT system using water from its aquaculture operation.

The question.....Is Aquaponics really the most economical way to grow anything?.....is an interesting one.

I'd probably narrow it a little and ask "Is the commonly used recirculating flood and drain aquaponics system the most economical way to grow anything?"

The answer......probably not!

Advocates of the Speraneo model (flood and drain grow beds) often forget that aquaponics is the combination of recirculating aquaculture and hydroponics.....in all of its forms.

Gary

[arachdog]

Run to waste doesn't mean that they dump all of the solution after a single pass.

Well everything I've read tells me that's exactly what it means.

In fact, a correctly tuned run to waste system will actually waste very little nutrient solution

I'm not sure if that's true or not. I think its more of an intrinsically wasteful system. If it is true then they must be very hard to tune because RTW certainly has a polluting reputation.

.....and, even then, the bit that is drained off at the end will often be directed to other plants.

Then's its not a true RTW system.

But anyway I've had a re-think and decided my argument about the cost of nutrients was poorly phrased. I should have acknowledged that aquaponics (assuming that the aquaculture portion is profitable in its own right) produces nutrients for free. Which is obviously cheaper than a commercial hydroponic solution. It's just I think that the savings (including the profit from the fish) made here aren't that significant when you look at the whole system.

I'd probably narrow it a little and ask "Is the commonly used recirculating flood and drain aquaponics system the most economical way to grow anything?"

None of what I'm saying here is a comment on any particular design of aquaponics system.

What I'm talking about is the efficiency of the nutrient solution that can aquaponics can create. Until that starts to approach (it can be slightly less, since there are savings made elsewhere in the system) what a commercial hydroponic solution can achieve then hydroponics is always going to produce a better return on investment no matter how cheap you can get obtain the grow beds.

[GaryD]

The message that is coming out of many commercial operations is that the plants are the main game and that the fish are simply the means to an end.......to provide nutrients and to meet a given portion of the system costs.

If the financial modelling of a commercial operation is premised on the vegetable or herb production, then the fish, having provided the nutrient solution for the plants, are a bonus.

Interestingly, this is also the message that's starting to emerge from the more sensible end of the backyard food production front, too. What experience (particularly with Australian species) has taught us is that successful (and that means consistently safe) operation of a standard small flood and drain system requires very modest stocking.

Anything else requires solids removal and rigorous management.......just like any other type of aquaculture.

[bigdaddy]

Hi everyone,

Very interesting question arachadog.

Rather than get down to specifics and figures, I thought I would talk generally,about this, and see what people think.

My understanding of aquaponics and its benifits are, the systems both privately and commercially at the same ratio,as you mentioned are, mainly used for the plants and the benefits of the fish to our bodies and pockets are secondary.

I've read, the main non benefits of aquaponics, mainly coming from people who are opposed to them are,
financially - the costs of purchasing and implementing the systems and,
environmentally - the amount of energy used to make the systems.
I've also noted that a lot of people who are for aquaponics don't talk about this aspect much.

I guess, if you are considering aquaponics as a commercial venture,the same viability and environmental impact rules apply,as with any other commercial venture.

It's interesting to note that some people are prepared to go to solely aquponics commercially in Australia,whist there are still a lot of people still keeping to hydroponic only.

On a slightly different tack.The largest or tallest building in the world is either being constructed at the moment or about to be constructed in China, has employed the hydroponic technique solely to feed the building's substantial garden.
I would of thought the building's engineers, would of considered aquaponics along with other techniques before deciding on hydroponics.

I just thought I would throw those thoughts out there for you guys to think and talk about.

Cheers.

[Outbackozzie]

Hydroponics is easier. Thats the only reason it is preferred over AP. Nothing alive to kill in Hydro.

My commercial system is fully AP, and it is going to be highly stocked. I am getting around the need for mechanical filtration by running a ratio of around 4:1. The advent of sequencing valves has enabled this to become viable.

[arachdog]

Hydroponics is easier. Thats the only reason it is preferred over AP. Nothing alive to kill in Hydro.

My commercial system is fully AP, and it is going to be highly stocked. I am getting around the need for mechanical filtration by running a ratio of around 4:1. The advent of sequencing valves has enabled this to become viable.

Yeah I dont know ozzie. Run to waste is probably easier but I think recirculating hydroponics is actually more complicated. Daily pH, and nutrient adjustments as apposed to lobbing a bit of food in once a day and perhaps weekly pH adjustments.
I don't think you've got the right idea by trying to avoid mechanical filtration. Increasing you growbed ratio is only going to delay the inevitable. Eventually your growbeds are still going to block up and become anerobic. Backwashing a filter once a day is a damn sight easier than trying to manually clean the **** out of tonnes and tonnes of media.
I'm not sure what sure what you mean by the advent of sequencing valves. I don't know why you would want to use them, and I wasn't aware that there was anything new about them.

[Ravnis]

http://www.greenhousecanada.com/content/view/965/38/

Interesting read.

The fact that a FORD motor company plant may turn into an aquaponics plant also makes one wonder. Vermiponics is probably the way to go if you dont want fish. But if you want fish or know people that do... then aquaponics is better, hands down.