Whilst you’ll want your filter to cycle the right volume of water per hour, bear in mind that goldfish prefer low flowing water. HOB filters may be a better choice as they are less expensive, easy to clean, and have the power to process the required water volume. Hang on back (HOB) or canister filters are the best types to achieve this.Ĭanister filters are very powerful and quiet but can be pricey. So for a 40-gallon tank, the filter would need to process around 160 gallons per hour. To deal with all that waste, your filter needs to be able to cycle through all the tank water around four times an hour. Critically, it also houses the beneficial bacteria needed to remove toxic ammonia. The right filter will help to clear particles and waste from the water. Goldfish need very clean water to stay in good health so adequate filtration is a must. You also only need around a capful per 100 gallons. You can do this by using a water conditioner. Whenever you add extra tap water to your tank you must condition it.Ĭhlorine and chloramine are the main chemicals used to treat tap water, but they are toxic to fish and must be removed. The Right Water Conditions For Goldfish Water Conditioning A leaning tank can cause an imbalance of pressure on the seals leading to potential leakage. But it will outgrow it in only a few months, so ideally it’s better to start with the larger size. You can start a juvenile goldfish in a 10-gallon tank. This gives them that extra bit of room to grow. If starting out with two fish, I would personally go for a 40-gallon tank.
So for two goldfish, a 30-gallon tank would be the minimum size needed. You should then add 10 gallons for each additional fish. The minimum tank size for a single adult goldfish should be around 20 gallons. This makes the tank more dilute, and so easier to deal with changes in water conditions. But a larger tank also makes a difference as it holds more water. Tank Size: Effect On Waste And Water ConditionsĪs feces and excess food break down, they not only consume oxygen but also produce ammonia which is toxic to fish.Īmmonia is mainly dealt with by filtration and the Nitrogen Cycle, which we’ll cover later.
But they generally have high oxygen demands under normal conditions. Goldfish can sometimes survive for periods on low oxygen levels. This type of tank also means a greater air-to-water surface ratio. So a shallower, squatter tank is a better choice than one that is tall and thin. They are also primarily horizontal swimmers. Goldfish are constant foragers and like to roam the substrate searching for food. It will also allow space to swim, hide and explore. To provide proper goldfish care, a larger tank will give your goldfish the room they need to grow. Hearty varieties generally range from 5 to 9 inches depending on type, but they can get bigger.įancy goldfish are usually an inch or two shorter but can be taller due to their rounder body shape. Keeping a goldfish in a small, unfiltered tank or goldfish bowl is very likely to stunt its growth. With the massive amount of information available online, you can gather all the info you need on any fish rather quickly.Firstly, let’s debunk the myth that goldfish only grow to the size of the container you keep them in. The point is, while a knowledgeable employee can be a big help, you don’t need to rely on these folks to tell you what is best for your tank. In my opinion, those kinds of stores should not be selling fish. In some stores, the same staff member that sells fish might also work in automotive or sporting goods. Some are very knowledgeable, but others are not. Never make choices solely based on what the staff at the pet store tells you. Find out what kind of water and space they require, whether they are territorial, if they will try to eat other fish, or if they are simply too aggressive to keep in a community setting. As I always say in these articles, the most important thing you can do to make sure all of your fish get along is to do research before you bring them home.