A small backyard aquaponic system supplying fish and vegetables sounds like a self-sustainability dream. Here is what to avoid to ensure it doesn’t become a nightmare.
Grand Plans, Not So Grand System
Poorly designed and constructed systems are the leading cause of problems in DIY aquaponics systems. When you start planning an aquaponics system you will initially build a plan based on how many fish you want to grow (often a lot!). However as you start preparing to build the system, concessions are often made that result in a less than ideal environment for the fish and plants. Types of concessions that impact the final system build are:
Limitations of budget
Even for a DIY system the costs can start to add up. Once you start calculating the costs of the fish tank, growbed tank, growbed stand, media, pump, and fittings, you might find that the costs are higher than you thought a DIY solution might be.
Either the area you have set aside is too small to fit a decently sized system or you are forced to install the system in a less than ideal location (too much shade). Location issues are sometimes caused be a perception that the system is going to be ugly (usually by the other half!), so the area unused is usually hidden in an unused area of the garden (i.e. it’s not a good place for anything so we might as well but an aquaponics system there).
Proving the concept
Before spending more on a larger or professionally built system, some prefer to build a small test system to prove the concept to themselves. Ironically these small systems are less likely to be successful and often cause the builder to spend more in upgrades.
The main logistical challenge is to raise the growbed above the fish tank in a classic flood and drain system. Growbeds are exceptionally heavy and many reduce the size of the growbed to make it more feasible to stand it above the ground. This affects the filtration capacity of the system leading to poorer water quality for the fish.
Limited by available materials
Depending on where you live, there just may not be supply of suitable materials (fish tank, grow bed tank) for successful aquaponics systems. This leads to purchasing of the closest most suitable materials (that sometimes aren’t suitable) which won’t help you reach the results you are looking for.
Aquaponics definition of ‘Impatience’: The urge to stock a fish tank full of fish on completion of a DIY project or getting a new system.
Aquaponics systems need a lot of time ( at least a year) before they can be stocked to capacity, however the urge to stock a new system full of fish has led to a spectacular failure of many an aquaponics system.
Too Many Fish
Overstocking aquaponics systems is a mistake almost everyone makes once. The idea of growing a large stock of fish in your backyard is tempting, with the costs and effort not seeming worthwhile unless you are growing a lot of fish.
Start small: Small fish, Small number. Let your system grow with your fish. Write off your first season and build up fish numbers in future seasons.
The more I feed my fish the faster they will grow! True in part, however don’t forget the result of more feed….more waste! Unless your growbed (filtration system) is capable of filtering the excess waste, substances toxic to your fish will accumulate and cause you problems.
Don’t feed your fish if they aren’t feeding. Throw a couple of test pellets into the water and if they are quickly devoured then it’s fine to feed your usual amount. If the pellets aren’t taken in the first 10-20 seconds it’s likely the fish aren’t feeding so don’t feed them any more.
Lastly, remove uneaten fish foods. Fish feed that sinks will rot on the bottom of the fish tank, and quickly because a problem if it starts to accumulate. A bit of feed left on the bottom of the tank for a few days is fine, even if you do a spot clean once a week you are not likely to run into problems. Just don’t leave it to build up over time.
Aquaponics systems are a mini ecosystem that when established will mostly manage itself. While your system does a great job of keeping itself maintained it does require some for example:
Checking for excess algal growth (including inside pipes).
Clearing debris than might get sucked into the pump.
Removing expired plants and replacing with new seedlings.
Over care can be as much as a problem as under care. It’s exciting to have an aquaponics systems however it’s important to leave it to its own devices in order to setup the natural systems that will manage it in the long term. Cleaning the system (unless absolutely necessary) can set back the system and the media in the growbed should remain undisturbed (definitely no cleaning required!)
The great thing about an aquaponics system is that you need to fish daily. This means that you are standing in front of your system every day and are very likely to pick up on anything that needs to be done.