Channel catfish are the most common substitute for Tilapia when they are illegal to raise. The channel cat is also prized for its flavour and is economically viable to grow as the powerhouse for the aquaponic system. It does require some larger tanks and prefers good currents. The pumps and water movement required to supply the growing beds of a commercial facility are usually quite adequate to the needs of channel catfish.
Channel catfish Ictalurus punctatus is he most common catfish in the United States and is regularly fished in swift moving streams and other location where there is adequate water movement. The fact that it is a good food fish makes it quite popular with aquaponic establishments who are prevented from keeping tilapia. The are quite adaptable in the temperatures thay will tolerate – being able to live in the range between 35 to 85 F. However they do best in the mich tighter range of 74 – 84F. These are also much better temperatures for the root of the plants being exposed to the water in the grow beds
They are able to accept low oxygen situations for a short time, but do need enough disoolved oxygen in the water. A slight disadvantage over the Tilapia is that channel catfish grow slightly slower, requiring between 12 – 18 months to reach a salable size. When sold by weight, they are somewhat less profitable as well, since they average a quarter pound less than Tilapia. The average sale weight for a channel cat is about 1.25 pounds.
Channel Catfish in the Home Aquarium
Channel catfish require a very large tank, so unless, as a home aquarist, you are looking to grow out fish for the table, this is probably not the fish you are looking to keep. They are active swimmers, but do not sport the colours that are often an attractive feature for the home tropical fish keeper.
If you prefer big fish and have the aquarium to house them, channel catfish could be a useful fish to grow for the table. However they re not recommended for small to medium tanks as they will outgrow the system and require relocation. Since that is not the aim of the home aqurist, it is much better to find other fish that are more suited to home aquariums to use an aquaponic filter.