* Temperature Requirements: Goldfish prefer cooler water (68-72°F) than most tropical fish (78-82°F). Maintaining a comfortable temperature for both types of fish can be challenging.
* Water Chemistry: Goldfish produce a lot of waste, making the water harder and more alkaline. Tropical fish thrive in softer, more acidic water.
* Feeding: Goldfish eat a lot and often create a messy environment with leftover food. Tropical fish are typically more delicate feeders.
* Tank Size: Goldfish need a larger tank than most tropical fish.
* Aggression: Some goldfish can be aggressive towards smaller, more delicate tropical fish.
Exceptions:
* Coldwater Tropicals: There are a few tropical fish that tolerate cooler temperatures, such as some species of danios and barbs.
* Larger Tanks: In a very large tank with proper filtration and water changes, you *might* be able to keep goldfish and compatible tropical fish together. However, this requires careful planning and monitoring.
Best Practice:
* Keep goldfish in their own dedicated tank with other goldfish or compatible coldwater species.
* Keep tropical fish in their own dedicated tank.
This will ensure that all of your fish have the best chance of thriving and living long, healthy lives.