Tropical Fish and Goldfish Should Not Be Mixed

One of the most common questions I get asked on a frequent basis relates to Goldfish and Tropical’s – many new aquarists don’t fully understand why other hobbyists are always saying “Goldfish must be kept with Goldfish.” And that’s completely understandable!

Very few people elaborate further on that statement, probably because they understand the reasoning themselves so it doesn’t seem important anymore. Here’s a brief explanation of all the key reasons why you should keep your Goldfish and Tropical Community fish separate.

1. They require different temperatures to thrive. The first reason that really stands out once you start researching the care of each type of fish is the required water temperature. Goldfish are a coldwater fish, and while they may do fine in water around 70 degrees F you will not see their best potential if you keep them in water that is too much warmer than that. On the other hand, tropical fish do best in water ranging from 74-78 degrees F – and sometimes much warmer than that! A tropical fish that is kept below 74 degrees F will become lethargic, quit eating and will be generally unhealthy all the way around.

2. They do not have the same dietary requirements. Goldfish will not do well on a diet that is meant for the majority of tropical fish. They require a diet that is very rich in fiber so that they do not become constipated. Unfortunately, constipation can become a major issue with some Goldies and lead to death.

3. Goldfish get too large and Tropical fish stay too small. The average size for a fancy Goldfish (the one that looks like an egg) is between the size of a tennis ball and a softball, and the single-tail varieties get even larger than that– the majority of tropical community fish will never even come close to reaching that size! Combined with their size and huge appetites, your Goldfish will soon start to look at the other fish in the tank as a potential snack. Once this happens, you will eventually come home to find a very fat Goldfish and no Tropical’s left in your tank after your Goldie has reached adulthood (even sub-adulthood for some breeds!).

4. Goldfish are way too messy. Because of their large appetites and messy eating habits, Goldfish excrete boat loads of ammonia every day. This quickly makes a toxic environment for some of the more sensitive species of tropical fish.

In order to keep Goldfish and Tropical’s together you would have to compromise some aspect of care for at least one type of fish – the concept behind that is completely counterproductive in my eyes since the whole point of keeping fish in captivity is to offer them an environment in which they will thrive so that they will be a pleasure to watch.

If you feel that I have missed a key reason please leave a comment below. Likewise, if you don’t agree with me and you feel that tropical fish can live in perfect harmony with Goldies, I would love to hear your input on this debate! I do not delete comments that disagree with my point of view.