When designing a system, it is important to understand the benefits of including certain components.
IBC Tote vs. Round (Circular) Tank
At NW Tilapia, we have used both IBC totes as well as round tanks. The benefit of using IBC totes over a round tank is the initial cost. The cost of a 275-325 gallon IBC tote is from $0 to $150. The cost of a 300 gallon circular tand, is about $320. The negatives of an IBC tote is the amount of fish you can put in the tank as opposed to a round tank. The semi square IBC tote encourages waste buildup in the corners of the tank. The buildup of fish effluent can cause ammonia spikes, and thus endanger the fish's health. As a result, we encourage our customers to stock approximately 1 fish per 3 gallons (100 fish total) in an IBC tank.
In a round tank, we have successfully raised 1 fish per 1 gallon (a 1:1 ratio). When you realize that you can raise 3 times the fish in a circular tank, the investment no longer becomes a reasoning point, since the investment is easily paid back within the year you use it.
An additional benefit of a round tank is the cost savings, per fish raised, in heating requirements. If you live in an area where you experience colder winters, maximizing your fish per gallon of water is a crucial point to consider. It takes approximately 2-3kw of heating power to keep a 300 gallon, un-insulated tank, between 70-75 degrees (in freezing weather). So, maximizing your stocking potential, is the difference between success and failure.
With all that said, NW Tilapia has used IBC totes specifically for breeding pens and fingerling tanks.
Solids Separator vs. No Solids Separator
There are many YouTube videos and systems that are encouraging the pumping of fish waste, into the grow beds. "Just put redworms to break it down", they say. Well, there are some things you should know, before you go that route.
If you only intend to have a few fish in your system, there will be no problem with this idea. However, if you are maximizing your growout potential, you must realize that each fish, will consume about 1.5 to 2 pounds of food in 1 year. Now, imagine that you have a 300 gallon round tank, with 300 Tilapia in it. After 12 months of feeding, you would have fed 450 to 600 pounds of food to those fish. You would need many, many, many pounds of redworms to process all that waste. Additionally, redworms excrete the organic matter they eat, in what way? A solid form...worm castings. So, where do the worm castings go to? The plants can only benefit from water soluable nutrients. To come to the final conclusion, sooner or later, it is you that will have to remove the solids from a system that does not integrate a solids separator. And, for most individuals, it usually comes with a loss of some/most of your plant crop, due to the anaerobic environments that the excess waste causes.
Biofilter vs. No Biofilter
A biofilter is a designated area where nitrifying bacteria can establish itself. For aquaponics systems utilizing all, or a majority of raft bed or NFT channel, you will have a need for a biofilter. If you are utilizing flood and drain media beds, these beds may provide sufficient grounds for the bacteria to establish.