5 Pet Goldfish Disadvantages: Are Goldfish Right for You?

You’re all set to buy pet goldfish from the pet store. There’s only one problem. Have you really thought this through? Have you weighed the pros and cons of goldfish care?

The Internet is flooded with goldfish myths and misinformation. Just browse the Web, and you’ll see tons of advertisements and catalogs featuring goldfish bowls (you do know pet goldfish shouldn’t be kept in bowls, don’t you?). In fact, most goldfish won from carnivals or bought from pet stores are dropped into small glass bowls without a second thought.

Photo by Erik Charlton (Flickr)

With so much bad information circulating the Net, it’s sometimes hard to separate fact from fiction. I was just talking to someone the other day about why most goldfish and tropical fish shouldn’t be kept together in the same tank.

Of course, going through all of this information and siphoning out the truth from the myths is a whole different story and deserves a new article of its own. The fact of the matter is: You can’t always trust what you hear. And one wrong move can be detrimental to the well-being of your goldfish.

Take it from a fish keeping veteran. I’ve been raising pet goldfish for over 10 years and have seen my share of misinformation. But one thing I’ve learned from all these years of fish keeping is how important it is to do your research beforehand – don’t just depend on what you hear and don’t just raise goldfish blindly. If you want to get it right the first time, you have to know what to expect.

Goldfish care is a complex topic and many people end up buying pet goldfish without really knowing how to care for them. They’ll make mistakes and those mistakes will cost the fish their lives.

5 Reasons Why You shouldn’t Buy Pet Goldfish

I’m going to set it straight, right here and now.

By the end of this article, my hope is that you’ll have a better understanding of what is required at the very minimum to actually care for pet goldfish, the dos and don’ts of goldfish care, and what is expected from you (as the fish owner) before you buy your first goldfish. And if you don’t think pet goldfish are right for you after reading this, that’s fine too. There are plenty of other freshwater fish that have less requirements and aren’t as taxing on your time (bettas are another personal favorite!).

We covered the benefits of goldfish care already, so I won’t talk about those here. But let’s take a look at some goldfish care disadvantages.

• Pet goldfish need a large tank and plenty of space to swim around. It isn’t just about size. While goldfish do get pretty big, they also excrete more waste than other species of fish. In fact, goldfish are known for the mess they make and such mess can quickly pollute a 5-gallon or even 10-gallon tank with dangerous levels of ammonia. Unless you plan to upgrade your tank within the year, a single goldfish should never be in an aquarium with less than 20 gallons. Each additional fancy goldfish should then receive 10 more gallons of water (two goldfish can fit comfortably in 30 gallons, three in 40 gallons, and so on). You can read more about this in my goldfish tank guide. Of course, aquariums can be pretty pricey. It’s okay to start small and upgrade your tank as you move along. But never, ever put pet goldfish in a bowl. There are goldfish specific kits available at pet stores that advertise goldfish bowls, but these are generally very bad for your fish – some folks even go so far as to call them cruel!
• Goldfish need a powerful filtration system (or even multiple filters for large tanks). Because pet goldfish excrete lots of waste, they require a power filter in order to keep oxygen circulating and ammonia levels down. While tropical fish do quite well with those regular filters packaged in aquarium kits, goldfish really need more than those kits will offer you. I recommend a filter with at least 10 times your aquarium volume. For example, a 20-gallon tank would need a flow rate of 200 gph (gallons per hour). I personally use a Marineland Penguin Power Filter and haven’t ever needed to replace it (it has lasted me years). Just rinse the filter out with warm water from time to time and you shouldn’t run into trouble.
• Pet goldfish can quickly destroy a planted aquarium. Goldfish are primarily plant-based and love nibbling on and uprooting aquatic plants. So if you already have an aquarium set up with lots of green scenery or if you plan to add live plants to your tank later on, you should be aware that those plants will likely just become a salad bar feast. Of course, there are other ways around this. You can most certainly keep aquatic plants with your goldfish without worrying that those plants will disappear before the week is out.
• Goldfish have sensitive digestive systems. Goldfish don’t have real stomachs and so can quickly develop problems if they eat too much food at one time or food isn’t prepared in a certain way. In fact, fancy goldfish are especially known for their swim bladder and buoyancy problems. You can help aid digestion by feeding your goldfish lots of greens and quality goldfish food. Not all brands of goldfish food have equal nutritional values, and many commercial brands will include fillers that offer very low nutritional content (Hikari Lionhead pellets, Omega One Sinking Pellets, and New Life Spectrum Pellets are trusted brands that I use and offer only the highest nutritional value). Overfeeding can also cause problems, both with the water quality and your goldfish. Just remember never to feed your goldfish outside of feeding sessions, no matter what begging antics your goldfish will try to soften your resolve.
• Goldfish can’t be kept with tropical fish. Goldfish are actually coldwater fish and require cooler temperatures to thrive (around 65°F or 18°C). Despite what many people think, pet goldfish should never be kept with fish that enjoy warm water temperatures (read my article explaining why). Ideally, you’ll want to keep your goldfish with other goldfish of the same size and body shape. For example, fancy varieties shouldn’t be kept with common or comet goldfish because they have different body types (fancy goldfish are slower swimmers and won’t be able to keep up during feeding time).

If you want your pet goldfish to live long, healthy lives, you need to commit to providing them quality goldfish care. Arrange to feed your goldfish on a daily basis and set time aside during the week for water changes. Organize a tank cleaning schedule and regularly check to make sure aquarium equipment is functioning properly. Your goldfish depend on you for their care. They can’t do it themselves, so you need to be open and committed to getting it right the first time.

What Do You Think?

Do you have pet goldfish? If you do, what tips can you offer new pet owners? Write your responses in the comments below!