Choosing a fish tank for your aquaponics system is very different than choosing one for an aquarium. There are special considerations you need to make because of its correlation with the grow bed, both share many of the same requirements for materials. Here’s a brief guide to help you choose the right aquaponics fish tank.
Aquaponics Fish Tank Requirements
- Must Be Waterproof – It might seem obvious but it’s vital that your fish tank is watertight, meaning that there are no leakages around where the plumbing fittings are inserted. Use rubber gaskets and marine grade silicone to prevent any leakage.
- Must Be Sturdy – It must be strong enough to hold the total mass weight of water which weights 1kg per liter, plus you have to take into account the added pressure from flowing water.
- Must Not Be Toxic – It’s essential that your fish tank has no toxic material as it’s the home of your fish which subsequently will provide nutrients for other living organisms in your system including plants, bacteria, worms and other insects.
- Must Be Insert – Make sure that the material doesn’t affect the chemical balance of your system such as the pH and ammonia levels. It’s not a good idea to use metal containers unless they’re lined because they can corrode and affect the balance.
Grow Bed : Fish Tank Ratio
So the ratio of grow bed to fish tank must be right. The total volume of all your grow beds that is connected to a single fish tank should be at least of equal volume of your fish tank. It’s ideal for a beginner to take on a simple 1:1 ratio since it’s the simplest design for a basic Flood and Drain type system.
However, you can safely increase this to a 2:1 ratio and even more when you’re ready to do so. This will give better filtration in your system and added long-term health benefits for your fish.
Fish Tank Size
The size of your fish tank depends on what type of system you have. It also defines the type of fish you can grow and how flexible your system can be.
A small indoor desktop aquaponics system that’s aquarium based, you’ll be limited to using just aquarium fish. However, if you want to grow larger fish that you can eat such as tilapia then you need a much larger tank.
If this is the case, then you need to make sure that your fish tank is at least 45cm in depth and is able to hold at least 190 liters of water in order to grow a 30cm plate-sized fish.
The shape of the fish tank isn’t very important but ideally, you would want a round or oval shaped tank simply because the flow system of rounded tanks tends to minimize the likelihood of dead zones, areas within the tank where there’s little water flow and chemical exchange.
Also, a short and wide fish tank is better than a deep and narrow one due to the fact that they have a much higher water surface area to water volume ratio. This results in more efficient gas exchange for your tank.
Be careful where you put your fish tank. It’s common sense not to put it on top of a weak structure as it may collapse, and keep it away from an area where the temperature could change such as in direct sunlight.
Certain species of fish are more suited to cool environments while others hot, and if you were to change that, then your fish can die. It’s also a good idea to cover up the fish tank so that things cannot fall in and to reduce the amount of light penetrating the tank (fish do not need light to survive).
Remember that the most important things about your aquaponics fish tank is that it’s strong, non-toxic and watertight. You can purchase large stock tanks to fulfil this purpose but make sure that you invest in a good one. Here are some aquaponics fish tanks that fit all the criteria of above.
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