Aquaponics 'Claimed' Disadvantages

Claimed Disadvantages:
by Matthew McCarthy
credit to :sites.google.com/site/aquapanaponics/4-project-updates/advantagesanddisadvantagesofaquaponics

• Can be expensive to setup as the system requires pumps, tubing, and tanks/beds. This is certainly true though it doesn't necessarily need to be. A small backyard system purchased complete from an aquaponics retailer can cost over $2,000 installed and the larger backyard systems capable of feeding a family between $5,000 and $10,000. Though if you are willing to devote some (or a lot) of your own time and energy then I think similar systems could be built for 25-50% of these costs (this is my guestimate). Grow beds and fish tanks can often be obtained for free (in western countries) and gravel obtained from the local river, though components such as pumps and backup power supplies will still need to be purchased. 

• You need a green house to really have a good aquaponics system. I guess this depends on what type of climate you live in. A green house can be advantageous to provide heat in cold winters, protect the system from heavy rains and keep out pests. This is also true for soil based gardening.

• Setup requires technical knowledge of aquaponics systems and hence is possible to make mistakes. True - there are stories around of people who loose fish and give up on their aquaponics system early on and there is some knowledge required to establish the necessary bacteria within the system. In a lot of cases these failures are because systems have fish stocking rates that are to high. We have yet to stock our system with fish so I can not provide a lot of information from our personal experiences though the initial establishing of bacteria (known as cycling the system) was very simple and took a lot less time then the average system cycling time.

• Water needs to be constantly monitored to make sure the water quality is OK for fish. This is certainly the case during the first couple of months. After the system has matured water testing is usually carried out only once a week unless there are problems. Seems very complicated for the amount of fish I will get. Yes keeping a healthy environment for the fish is where most of the complexity lies within the system. Water needs to be free of toxins (especially ammonia and nitrite) and also have enough oxygen for the fish you are keeping. This can involve adding extra aeration sources and making partial water changes to improve water quality. Stocking fish at a lower density will in most cases reduce the pressures on a system and make it more tolerant to changing conditions and less likely to suffer from the above problems - though this means you will have less fish to eat.

• Aquaponics requires electric energy input to maintain and recycle water within the system. In most cases you will need to provide electricity to run a water pump and possibly aeration pumps as well. We run our 80w water pump for 5 minutes every hour to flood and drain our three grow bed buckets. As we currently run the pump day and night this amounts to 2 hours of usage a day - so similar to having a light in your house (with an old style bulb) on for the same length of time. We plan to add another three grow beds to the system so this will increase our electricity usage further. At this stage we have not made any attempt to optimize the flood/drain cycle so there may be opportunities to reduce the number of times the system is flooded each hour or to not run the system at night with little impact to plant growth. 

• If one or more components fail this could lead to the loss of fish and or plants. In this regard you are dependent on using reliable technology (and back up systems) to ensure that your fish, which require oxygen in the water, remain alive an healthy. Your plants are likely to be unaffected in the short term, as the growing medium will likely retain more then enough moisture, though if the fish are not provided enough oxygen, they can suffer and die. This is the same situation for aquaculture systems.

• You can't grow root crops. You can grow pretty much anything in an aquaponics system from fruit trees to root crops, though depending on the type of growing medium potatoes and carrots may grow into some weird shapes. Most people focus on growing leafy vegetables.

• Ok so you don't have to add fertilizer or nutrients but you do have to provide fish food. Yes you do, the fish eat the food and their waste is used to produce nutrients for the plants. Of course you also have to feed fish in an aquaculture system and in an aquaculture system fish waste is not used in such a productive way. Fish are some of the best animals at converting food into body mass (different fish species vary) and so are an efficient way of producing meat and protein. Most people buy commercially available fish food for their fish although many people supplement this feed by growing worms, duckweed and other plants and animals.