Hi All …

While I am not an active member, I am an avid reader and consumer of information….

I come from a large projects environment and for some time now have been trying to figure out why Aquaponics (AP) has not caught on in mainstream farming in a “Big Way”? Aside from the usual barriers to new technology or ideas there must be something else that is hindering the commercial application of this technology….. I thought I would post some thoughts and see what other members think ….?

Is this new unproven technology ? …. The word may be unfamiliar to some, but the concept is readily accepted by many, indeed there are a number of farms in the US which have been recognised and certified as organic AP producers. Hundreds of back yard enthusiasts have proved that AP works, however scaling up seems to be an issue…??? But what is the issue with scaling up? The minute we scale up we are worried about profit, because well that is what scaling up is for … profit. So is AP unproven technology? At a backyard level NO

I believe there is a disconnect between the DIY / backyard enthusiast philosophy and a commercial approach to AP. Let me qualify that statement, I am not saying backyard does not work, it clearly does, but the same philosophy cannot be applied to a commercial setup……

Example 1 : I set up a small AP system at home using IBC containers…. 1000L tank, 1000L growbed, 500L odd sump, pump in sump, flood and drain system with gravel as the grow medium, a couple of tilapia in the tank. The system worked as it should have …. The fish grew and the plants grew…. Yes AP works… Can we take this system and make it into a commercial venture … my suggestion is…………. not with the same sort of thinking.

With AquaCULTURE (AC), specifically the farming of fish, the world is littered with fish AC projects which have failed…..and others that have achieved success …. What is the fundamental difference between the ones which succeed and the ones which fail? In my mind the greatest difference between these is the value of the product for sale at the end of production….. we have open systems, closed systems, filters of an infinite description, but at the end of the day the value of the end product reigns supreme as the key difference. Point in case look at the value of trout vs the value of tilapia….. food conversion rate is not dis-similar, value of end product is vast. As backyard AP enthusiasts we tend to tinker with the systems and more often than not marvel at our success but we like to have hardy fish as the lifeblood of the system and tilapia, carp etc fit this bill perfectly (I am not suggesting that there is an error in this approach from a backyard AP perspective) but they have little value at the end of production. So in summary commercial AP operations not using a high value fish are missing out on a serious revenue source. I am not suggesting that trout are the solution, there may be other options such as barramundi (sp) in Aus, the key is that the selected fish should be of high value, not simply the easiest fish to keep. If the fish are not high value then aside from the “organic” production method, there is no benefit in AP vs a system like Hydroponics, and the operator is looking after fish without the full financial benefit of doing so

The next key failure I believe is the failure of the systems to keep it simple, and the failure of the commercial systems to fully appreciate the cost of power. Certainly from an African perspective the cost of power is astronomical and will not come down any time soon, so systems should be simple and energy efficient. If we go back to my example above …. Perfectly good system, for a backyard enthusiast, but very poor power efficiency if scaled up. I needed a 2000LPH pump to pump the 1m head efficiently enough to effectively flood and drain the system….. this has a minor impact on my utility bill, but scale this up 1000 times and whoa, the effect is no longer negligible ….. Is the solution then not to eliminate the “head” requirement…. Bury the main tank into the ground, so that the elevation of the tank is very similar to or the same as the elevation of the grow beds ….. the efficiency of the pumps deployed are exponentially better…. Power usage is thus exponentially better. A deep water system could potentially eliminate the requirement of a sump all together – further eliminating the requirement for a pump that deals with head.

With small systems we tend to not worry about the solid waste produced by our couple of fish …. We may siphon it out once every two weeks, but further than that we don’t really worry about it. Experience with Koi has taught me that effective and efficient removal of solid waste is critical to maintaining water quality…. Should the same systems employed in koi ponds not be in place for commercial AP? Essential to this is the concept of “bottom Drains” the solids gravitate to the lowest point of the tank or pond and water pumped through the AP system is removed from this point, passing through something like a swirl filter to remove the solids before entering the AP grow beds

Commercial AP systems need to be viewed in a holistic manner…. It is a neat trick that you can grow plants from fish poop, but a trick it will remain until a high value fish is selected along with a high value vegetable crop, in an energy efficient system designed to cater for high stocking densities. Of course the final closing of the loop is to eliminate costly fish foods, while I will not discuss this in this first post, I believe that the trend towards protein recycling and the use of the humble maggot will ultimately solve this issue.



I am really interested in what everyone has to say about the above comments / thoughts … in summary

This is not a critique on existing AP farms in any means, really just discussion points........