Goldfish are one of the most common pets in the world. Each year, over 480 million goldfish are sold and millions of households keep at least one of the aquatic creatures as pets. They’re a simple pet to have and require little maintenance. When you think of goldfish, you probably think of one swimming around in a clear glass bowl on someone’s kitchen counter. Simple, right?
Wrong. Unfortunately, many goldfish are kept in conditions that are not ideal for their species. Goldfish can survive in a glass bowl, but they will not thrive nor reach their maximum life expectancy. To truly thrive and live their life happily, goldfish need an adequate aquarium and a filter. Before we dive into what a goldfish really needs, let’s learn about their history.
History of Goldfish
Goldfish originated in China more than 1,700 years ago. They are a domesticated version of a wild carp found in east Asia. Their ancestor was silver-grey, known as “chi”. At the time, it was one of the most common fish eaten in China.
But genetic mutations sometimes produced a fish that was a bright yellow, orange or red, and those fish stood out to both predators and people. Predators could clearly see their colors and they were quickly eaten. The opposite happened for people. Buddhist monks in particular took a liking to the brightly colored fish and started catching them to keep in ponds and gardens, rather than on dinner plates.
Soon, the fish became more and more popular. Legend has it that 9th century Chinese GovernorTing Yen-tsan found yellow chi in a pond outside the city and was drawn to them. He declared this specific pond a pond of mercy. In Buddhist culture, setting an animal free is a good deed, especially if it is rare, which the colored chi were at that time since they only formed from genetic mutations.
After that, it became common for these colored chi to be saved from a gruesome end on a plate and instead placed into ponds for safekeeping and admiration. Around 975 CE is when they became more common, but they were not thriving. They were still wild animals and struggled in domestic habitats for over 100 years. They hid from humans and would not eat the food provided for them. So for all those years, they evolved to become the domesticated version we know today.
Around 1240 CE, the distinction between wild and domestic Chi was more clear. These domesticated fish were now tame and ate the food they were provided. They became common in public mercy ponds, but also in private ponds and homes. As their popularity grew, so did the domestic breeding of the species. People began to experiment with breeding different color Chi to create new variations. By the 1500s, it was common to keep goldfish in bowls in homes, which made keeping them even more affordable. Due to this, breeding amped up even more, producing the hundreds of breeds today.
To give you an idea of the breeds today, Purnell’s Encyclopedia of Animal Life (1968) said the variations created were “monsters”. “To recite their names is enough to make this point: veiltail, eggfish, telescope, calico, celestial, lionhead, tumbler, comet or meteor and pearl scale. There are also the water bubble eye, blue fish, brown fish, brocade, pompon and fantail and many others.”
Goldfish Today
That leads us to goldfish today! Our beloved little colored friends make great pets for young caretakers because they are simple and require little to no maintenance. Or are they? There are quite a few requirements to keep a goldfish happy and healthy for a long time. No more sneaking out to replace a goldfish overnight after it dying after only a month. If you provide the proper care below, your goldfish can survive and thrive for years.
Tank Requirements
While tank requirements are specific to the breed of goldfish, there are a few general guidelines to follow. You may have heard the idea that fish only grow to the size of their tank, but that is not true and can be very harmful to the fish. Wild goldfish can reach up to 12 to 14 inches. Most goldfish need a minimum size of a 20 gallon tank. This is just for common goldfish, other breeds, such as comets require 50 gallons, or shubunkin, which need around 75 gallons to thrive.
A rectangular shape is best. Novelty bowls that feature funky shapes or complex designs are not ideal. The tank should be open and simple with defined edges.
Water requirements
It seems simple to just fill a tank with tap water and call it a day for your fish. That’s what many of us did as children. Scoop them out, keep them in a cup, and fill the tank. But a goldfish requires water at a very specific temperature. They are coldwater fish and their ideal temperature should be between 65 degrees and 68 degrees Fahrenheit. This does vary among the various breeds so it’s important to research what temperature your fish requires. You’ll need a thermometer to check this temperature often. The water temperature should never rise above 74 degrees Fahrenheit. If you keep a goldfish above 72 degrees Fahrenheit for long periods of time will cause oxygen deprivation, which basically shuts a fish’s body down. PH level isn’t critical, but is important and should be between 7.0 and 8.4.
Rapid temperature change or water pH levels can be fatal to goldfish, so it’s important to introduce changes slowly. You should regularly clean their tank, every four or five days replacing 25% of the water. Use conditioner-treated water and let it sit 24-48 hours before adding it to the tank.
Filters = Oxygen
So we know now that a bowl is bad. Is just a regular large tank fine then? Not really. Filters are essential. A filter pulls water through sponges and removes debris from the water. The filter also harbors good bacteria, which helps remove dangerous chemicals from the water.
The reason why a proper aquarium setting, especially a filter, is so important is due to oxygen. Goldfish can actually live up to 20 years, but often die prematurely due to improper conditions and care, especially from issues regarding oxygen. It’s important to understand a bit about the biology of goldfish. They take in air by absorbing oxygen in water through their gills, or by swimming to the top of the water and taking air in by their mouth. If your tank does not have a filter, the goldfish relies on mouth breathing only, which is meant more as an emergency method and causes immense stress on their body.
Goldfish need a lot of oxygen. This is why bigger tanks are best, they need more surface area to spread out the oxygen and avoid becoming deprived. Swimming to the surface is not begging for food, it is gasping for air. Adding plants to your fish’s environment is another great way to boost oxygen levels.
A filter also helps with excrement poisoning. Fish live 100% of their lives in their tanks, meaning they both eat and poop inside of it. Think of how filthy that could get even with weekly water changes. Goldfish produce nearly 10 times the amount of ammonia as a fish of a similar size. If they poop in stagnant, unfiltered water, they are swimming in their own waste. A lot of goldfish die in a bowl due to ammonia poisoning – created by their own filth. Their fins and gills get burned by their own waste and can lead to an early death.
Types of Filters
There are a few different types of filters and it’s good to explore which would be the best option for you. There are more filters than listed below, but these are two common types that are more affordable and better for beginner owners.
- OB Filters (Hang on Back)
These filters are the most common and affordable from the list. These hang on the back of your tank. To calculate the gallons per hour needed, which is the measurement these filters use, multiply the gallons of your tank by 10 to find this number. If you have a 20 gallon tank, you want a HOB filter with 200 gallons per hour. These are adequate filters, but not the best for goldfish.
- Canister Filters
Canister filters go underneath your tank. Water is pushed into the filter through gravity and then pumped back into the tank.
This is probably the best option for goldfish, because they offer a lot of space for good filtration. These also maximize water clarity. They must be combined with an aquarium stand though since they rely on gravity. These are a bit pricier, but worth it. Like OB Filters, these have a formula to calculate the gallons per hour needed. This time it’s the number of gallons multiplied by 5. A 20 gal tank would be 100 gallons per hour.
Filter Media
Now we’ve discussed the two best filters to use, but we still have to talk about what goes in the filter. This is known as filter media. Filter media is anything you put in the filter to produce clean water. There are two main types for a goldfish. The first is a sponge. These can be rinsed off which is great for a goldfish, as their poop can get rinsed right out. It’s also a more long term option. You want to ensure you buy a quality filter though, not just any old one. This is because a quality filter sponge can be washed and the helpful bacteria we mentioned earlier will stick to it, not wash right off like a cheaper one or one of a different type. This is not absolutely essential for goldfish, but is good to provide and ensures a clean tank.
The other component of filter media is biological media. This is by far the most important part and is 100% necessary for goldfish to thrive. This media comes in many shapes and sizes, and is a host for helpful bacteria to grow. This is the same bacteria mentioned earlier. It consumes ammonia, nitrate, etc. and turns it into less harmful chemicals. If there was nowhere for this bacteria to grow, the water inside the aquarium would quickly become toxic. Use as much of this media as you can. It’s great for your goldfish and helps them flourish.
What about Air Pumps?
Okay, so a filter is necessary. What about an air pump?
Air pumps are designed to push oxygen into the tank, which is essential for goldfish, as we’ve learned. You would think this sounds like a done deal and you should definitely have one in your set-up, but that is not necessarily true. An air pump is not required for a goldfish to survive. If your tank produces enough oxygen from having enough space, filtration and natural plants, then an air pump is not a necessity.
The amount of oxygen air pumps actually create is fairly low. You would think it is a lot because of the bubbles it produces. Your filter probably produces as much surface movement. As a general rule of thumb, you can see if you tank needs more oxygen by watching to see if the surface ripples. If you have a smaller tank due to space restrictions, you may also want one to help produce more oxygen. The same goes with temperature. Warmer temperatures need more oxygen.
So an air pump is not essential, but can be a nice addition if you think your tank needs more oxygen. Listen to your fish’s needs and watch their behavior to see if you notice them gulping for air. If you do, that’s a sign an air pump may be necessary.
Long Story Short
Goldfish are a beloved pet, but are not always kept in the ideal environment for their species. A filter is absolutely necessary for a goldfish to thrive in capacity and helps them reach their maximum size and life expectancy. An air pump is a welcome addition if the amount of oxygen in your aquarium is not sufficient, but if you set your tank up properly, it probably isn’t necessary.