Aquaponics has proven more popular with gardeners than with any other group of users. This is hardly surprising when we look at the extensive list of strengths afforded by this method of gardening. The ease of production, high rate of productivity and the inherent versatility of the system will ensure that aquaponic gardening is here to stay.
Strengths of Aquaponic Gardening
First of all, let’s begin with the strengths that are associated with aquaponic gardening.
i) 90% less water
All the water used is retained in water-tight containers and is prevented from draining away naturally. Only that lost through evaporation and transpiration needs to be replaced. It’s not surprising that aquaponics is so popular in Australia.
ii) No Digging
The plants are grown in lightweight media and the nutrients supplied via a constant supply of water. Furthermore there is no compaction and digging is a thing of the past.
iii) No Watering
The plants always have access to water and nutrients. Provided evaporation losses are made up there is consequently no requirement for regular watering. Certainly a simple ball-valve could be used to automate any top up required.
iv) Very Little Weeding
I wouldn’t say that there is no weeding but any weeds that do appear are very easily dealt with. As a result it’s almost a joy!
v) No soil borne pests and diseases
Lack of soil reduces the presence of both plant and fish pests and diseases. The life cycle of many pests are naturally broken in the absence of soil. Therefore there is little need to resort to pesticides.
vi) No messy soil
Often we gardeners quite like to get our hands dirty. There are times however, when we, and the kids, would rather be kept clean Clean conditions are specially welcome when growing and harvesting salad crops on a daily basis.
vii) No bending
It is often possible to have our grow beds at bench height. This makes gardening a real comfort. For many people, in many situations, this is often essential. It also helps to keep the plants away from ground level pests such as slugs, snails and even rabbits.
viii) Greater productivity
The constant supply of water and nutrients allows closer spacing of plants than would normally be the case. Growth rates are also generally greater and hence allows us to produce more plants in a given area.
ix) Great for polytunnels and greenhouses
Aquaponics lends itself remarkably well to polytunnel and greenhouse gardening. Both the fish and the plants , not to mention the gardeners, greatly appreciate the higher temperatures and protection from the great British weather.
x) Fully organic
This is becoming more and more important to more and more people. Aquaponics does not involve nearly so many pesticides and artificial fertilisers. These chemicals can often be completely eliminated. They are not necessary and besides, could have a catastrophic affect on the health of the fish.
xi) Excellent wheelchair access
Aquaponics should not restrict disabled gardeners in any way. Easy access to the plants is a benefit for everyone.
xii) Locate almost anywhere
Aquaponic Systems are not dependent upon local soil conditions as none is required. Equally, water availability is less important. Simple lighting kits can easily enhance light levels if required.
xiii) Versatility of aquaponic gardening
Finally, I’ve saved the most important strength ’til last. Aquaponics is nothing if not versatile. The range of fish and plants suitable for aquaponics is extensive and can be chosen according to individual preferences. Systems can be entirely functional or geared more to display. The choice is yours.
Weaknesses of aquaponic gardening
It wouldn’t be fair however, not to discuss potential weaknesses and pitfalls. None of these are insurmountable. Indeed, many people would see some of the following as strengths.
i) Fish keeping skills required.
Don’t allow yourself to be put off if you have never kept fish before. Goldfish are very hardy and easy to keep. They are cheap and readily available. It makes very little difference to the plants whether you keep goldfish or trout. They both produce ammonia and fish poo that supply your plants with all the nutrition they need.
ii) Need to balance fish and plant requirements.
Maintaining a natural balance is the name of the game here. Mother Nature tends to balance things out. Available food supply often limits the growth of the fish, plants and filter bacteria. How much food is eaten, how much ammonia is consequently produced and how rapidly this ammonia is broken down are all primarily affected by water temperature. By and large we do not have to interfere. There are limits however. We need to recognise these limits and know how to overcome them. The behaviour of the fish and the growth of the plants can tell us a lot about these limits. Without this experience we need to carry out routine monitoring of water quality. Inexpensive kits are widely available and cover most potential eventualities.
iii) Long term commitment.
All biofilters need time to mature. This can stretch to a few months under some conditions. However, there is little to do over this period and maturation will generally take care of itself. Keep feed levels low by operating well within the carrying capacity of your system. Once matured everything becomes well balanced.
Opportunities for aquaponic gardening
i) Excellent disabled access.
Engage with adults and children of all abilities. Wheel chair access is easy to incorporate. While the reduced need to bend is also very welcome for most of us.
ii) Use of redundant buildings
The addition of lighting, heating and ventilation systems has the potential to allow the use of many redundant buildings . Often these facilities are standing idle in derelict urban environments
iii) Year round production
All year round production is a real possibility that almost certainly offsets the additional costs of lighting, heating and ventilation involved.
Potential threats to aquaponic gardening
Finally, it is important to recognise that there are some potential threats to aquaponic gardening. As a result, careful system design, and a bit of preparation, usually turns a potential catastrophe into just a minor inconvenience.
i) Power failure
Fish depend upon the continuous operation of pumps to provide oxygen and clean water. As a result it is vital to overcome the threat of power failure by using an air pump as an additional source of aeration and have a spare water pump always available. Certainly keep fish stocking densities as low as possible. This will maximise survival times for the fish in the event of a power failure. Finally, there are more and more opportunities today to mitigate this threat by developing smart monitoring systems over the internet.
This is always a threat with any living creatures. In a farming situation with high densities of livestock this becomes even more important. Organic plant pest control techniques are essential in order to safeguard the health of the fish. Above all else, I must emphasis the importance of finding a good reliable source of disease-free fish.
Recommendations for aquaponic gardening
In conclusion, these are my personal recommendations to ensure success with any aquaponic gardening system.
- Start off small. Give your biofilter time to mature. Fish can grow remarkably quickly when operating systems below their maximum carrying capacity. Aquaponics is a rapidly expanding technology. Every system is unique so it’s really useful to get to know how your own system performs before committing to a full-scale operation.
- Install in a low-cost polytunnel. If you, like most gardeners, prefer a fully productive system rather than pure display then put your aquaponic system in a polytunnel or greenhouse. Weather proof gardening without bending is a wonderful thing for many of us.
- Install a small lighting system. Demonstrate the connection of light and plants. and extend the growing season.
- Pick the fish that’s right for you. Obvious really! To help you decide see our advice on best fish for aquaponics fish.
Finally, if you would like to find out more about aquaponic gardening I can recommend the following book – Aquaponic Gardening by Sylvia Bernstein
Have I missed anything out? Share your thoughts and help make this a better resource for everyone.