Aquaponics runs on a simple idea: fish waste feeds your plants, no soil required. But a system is only as good as the fish behind it — and if you want to breed or eventually eat those fish, that’s a nice bonus on top. Picking a species that matches what you want to grow matters, and walleye is one that beginners and experienced growers alike tend to pass over, even though it has a lot to offer.

Walleye — scientifically sander vitreus, and sometimes called yellow pike — is native to Canada and the northern United States. The name comes from how its eyes point outward, almost like they’re looking straight through a wall. That eye placement isn’t just distinctive-looking, though; it lets the fish see well in dark, deep water, giving it an edge when hunting. Coloring tends toward olive and gold with darker blotches across the body and a pale underside. One thing to watch for: walleye have a mouthful of sharp teeth, so handle them carefully.

Walleye Growth Rate

A fully grown wild walleye reaches about 31 inches and weighs close to 20 pounds, though you’re unlikely to see fish that large in a home tank. Most walleye caught in the wild run 12 to 20 inches and weigh 2 to 3 pounds.

In an aquaponics setup, growth is gradual. Fingerlings typically reach 3-4 inches and about a quarter pound by the end of their first year. By year two, they roughly double in size, landing around half a pound and 6-7 inches. At that point they’re generally considered mature, though they’ll keep growing slowly for the rest of their life — a 25-year-old female (females outgrow males) could theoretically reach 30 inches. In practice, tank size and the fact that walleye rarely live that long will keep them smaller.

Ideal Temperature For Walleye

Walleye do best in water between 68°F and 76°F, a range that’s manageable in most climates. Aim for a pH close to neutral, somewhere between 6.5 and 8 — typically about what comes straight out of your tap.

Pros and Cons Of Walleye in Aquaponics

Easy to Keep

Few fish are as low-maintenance as walleye in an aquaponics setup. They’re happy sitting in low light and feeding periodically, and they tolerate a decent range of temperature and pH — which makes them a surprisingly solid pick for someone just starting out.

Plant Compatibility

Because walleye handle a range of conditions well, they pair nicely with a wide variety of plants — handy if you’re growing several different vegetables at once.

Space Requirements

On the downside, walleye can grow fairly large even in captivity, and a single full-grown fish needs roughly 200 gallons of water. That means committing to either a large setup or keeping just one fish, which is risky if that one fish falls ill.

Feeding Challenges

Walleye generally resist commercial feed like frozen fish or pellets. Expect to keep a steady supply of crayfish, baitfish, prawns, and earthworms on hand to make sure they eat properly.

Not Much to Watch

If your main goal is feeding your plants rather than watching your fish, this won’t bother you — but walleye mostly stay parked at the bottom of the tank except at feeding time, so they’re not the most engaging fish to observe.

Difference Between Walleye and Saugeye

The saugeye is a near-identical relative of the walleye, with only a couple of distinguishing features. It lacks the white edge on the lower lobe of its tail fin, and it carries noticeable black spots on its dorsal fin — a marking walleye don’t have.

Walleye Aquaponics FAQ

What Does Walleye Eat?

Mostly other fish — walleye will go after nearly anything smaller than themselves, feeding most actively at dawn and dusk when light is low. Beyond fish, they’ll also eat minnows, crayfish, and worms.

How Big Do Walleye Get?

Wild walleye can reach 30 inches, but in a home tank they’re more commonly 5 to 8 inches long.

How Does Walleye Taste?

Don’t judge this fish by its looks — the flavor is quite good. Broiling or pan-frying works best, giving you a mild, only faintly fishy taste that some compare to chicken. A few people find it bland, though that usually comes down to diet and cooking method.

Can Walleye Be Kept With Other Fish?

Walleye are natural predators and will target any fish smaller than themselves. Tank mates need to be noticeably larger and unlikely to view the walleye as prey. Between that and their preference for dim conditions, mixing walleye with other species usually isn’t a great idea.

How Long Does Walleye Live?

The oldest documented wild walleye reached 29 years, though heavy fishing pressure means most only make it to 5 or 6. In a well-run aquaponics system, a walleye could potentially live into its mid-twenties if conditions stay favorable — and it isn’t harvested first.

Where Can You Buy Walleye?

Whether you want fingerlings or adult fish, your best source is a local aquaponics supplier or a reputable online seller. This helps ensure you’re getting healthy stock that hasn’t been exposed to unwanted chemicals.

Picking the right fish for your walleye aquaponics system comes down to a few things: you want it to thrive long-term, taste good, and reliably supply the nutrients your plants depend on.