We’ve been working our brains trying to figure out the best kind of fish to use in our aquaponic system. Tilapia seems to be the default choice. We’re going to use them for our trial system, but NOT the full-scale. Let’s talk about why.
Tilapia are very popular in aquaponics because they’re “hardy.” This is code for “nearly impossible to kill.” Since aquaponics is new, and most of the people doing it are new to growing fish, it makes sense to at least start off with something sturdy.
But here’s what we see in ’em. They’re invasive. They don’t have pinbones, but they have a big chunky skeleton that takes up most of their innards so there’s not much room left for meat and they’re a royal PITA to fillet. We get just cool enough in winter down here that they spend months every year half-hibernating-half-dead and threatening to go 100% dead on you every time there’s a cold snap. As fish go they don’t actually grow all that fast– especially if you put them on the low-protein diet that’s supposed to make them sustainability superstars. No omega-3 fatty acids to speak of. There’s zero profit in them because of factory farms pushing out cheap mass-reared tilapia. They’re supposed to be easy to breed– now, this is true! They breed to the point of stunting– they put all their energy into eggs and sperm instead of meat. The only way to get around that is to raise special hybrids (either bought in or painstakingly reared in a special tank), sex-reversal by putting testosterone in their food, or genetic modification.
As you might have guessed by now, we don’t like tilapia. At all. God bless ’em for being able to live in sewage. But we’re aiming to have water that’s a lot cleaner than sewage, so we shouldn’t need indestructible fish.
We’ll grow tilapia this year for the pilot scale when we’re making sure that the pumps and everything work. If we have a problem, a sensitive species would die and we’d have to throw them out and start over. Tilapia are more likely to survive and save us all the trouble. But once we get through the pilot scale, it’s time to move on to something a little more likely to pay the bills.