How Many Fish Can I Have?
Hi I’m Chris from Aqua Gardening.
So you’re interested in Aquaponics, and you want to know how many fish you can stock? Good question! There is a lot of factors which are involved, but if you follow our simple stocking guide you will get it right first time.
When growing fish in large quantities, you’ve got to consider the type of fish, the minimum and maximum water temperatures over a year, how much filtration you have, and of course, how big your fish tank is!
Fish all need oxygen to breathe in the water, and the amount of oxygen within the water varies with water temperature and the size of the fish tank. For a lake there’s a huge surface area, and plenty of space for oxygen transfer. For a narrow tank, the transfer through the water surface will be minimal.
If the water temperature rises in the lead up to summer, you will find the fish could be caught with low oxygen levels. The way to combat this is with an air pump. To prevent fish from running out of air, we offer cost effective air pumps and accessories in the links below the video.
Also, the more fish you stock, the higher the load will be for your filtration system.
If you are only relying the flood and drain cycle of media beds, such as clay balls, there will be a limit to how much you can feed the fish, and therefore how many fish you can stock as they all require at least a minimum amount of food.
We have a range of bio filters which will dramatically increase the filtration capacity of your system, see the links below to the recommended units.
Jade perch and silver perch are two types of fish that handle changing water conditions well, so these are two of the most common fish we recommend when you are just starting out with aquaponics. They also taste great! We recommend starting with 50 fish per 1000L of water, so that by the time they are getting close to 500 grams each you can start harvesting them or invest in better filtration or aeration equipment to accommodate their larger sizes.
Make sure you always leave around 10cm of free space between the water level and the rim of the fish tank so that if the fish chase each other around, there is less chance one will flip all the way out.
Commercially, fish may be stocked at higher ratios, but this puts more stress on the fish and the system, so we do not recommend going over this quantity when you start.
Keeping fish healthy is a science, but checking on their behaviour regularly and paying attention to how they are feeding are recommended.
When you purchase an aquaponics kit from Aqua Gardening, you will gain access to our members only video training library with expert tips on how to make your fish thrive! I’m Chris from Aqua Gardening – safe healthy food that grows itself!