In aquaponics—a system that combines hydroponics with aquaculture—selecting the right fish is crucial since they play a vital role in the ecosystem, providing nutrients for the plants. Here are some of the best fish choices for use in aquaponic systems, particularly for beginners due to their hardiness, ease of care, and compatibility with the growth requirements of most hydroponic plants:

1. Tilapia: One of the most popular choices for aquaponics, tilapia are hardy, fast-growing, and can tolerate a wide range of water conditions. They thrive in warmer waters and are also edible, making them a dual-purpose choice.

2. Goldfish: Often used in smaller, ornamental aquaponic setups, goldfish are hardy and can survive in various water conditions. They are not for eating but can produce a significant amount of waste, which is excellent for plants.

3. Koi: Similar to goldfish, koi are more of a decorative choice and are very hardy. They can grow large and live for many years, making them a long-term investment for an aquaponic system.

4. Carp: Carp are very tough and can survive in various environmental conditions. They are widely used across the world in larger aquaponic setups due to their size and growth rate.

5. Catfish: Catfish are bottom-dwellers and are excellent for aquaponic systems due to their hardy nature. They require minimal maintenance and are also edible.

6. Bass: Largemouth bass are a popular choice for larger aquaponic systems. They grow quickly, are resilient, and are edible.

7. Trout: Ideal for cooler water aquaponics, trout grow quickly and are efficient feeders, which makes them suitable for systems aiming for high output. They are also a popular culinary fish.

8. Bluegill: Also known as bream, bluegill are good for smaller home systems. They are hardy, easy to breed, and can be eaten.

9. Murray Cod: A robust fish that is well suited to larger systems. They grow rapidly and are a popular choice for eating.

10. Pacu: Related to piranhas, pacu are vegetarian and can be a good choice for systems designed for leafy plant production. They are not commonly eaten in all cultures but are known for their gentle nature in the tank.

When choosing fish for your aquaponic system, it's important to consider the climate, as some fish thrive in warmer waters while others need cooler conditions. Also, think about whether you intend to eat the fish or simply use them to support the plants. Each species has specific care needs, so choose those that best fit your environment and capabilities.