Goldfish Aquarium Filter Options
There are many different types of mechanical aquarium filters that will work to filter your goldfish water. You also have many things to considerer before purchasing an aquarium filtration system, including: the size of your tank (mainly the volume of water it holds), what types of fish and aquatic plants you have in it, how well the filter will assist in biological filtration, what your budget is and how much maintenance you are willing to preform.
Types of Filters
Sponge Filter: An inexpensive and easy to maintain basic filter that uses an air bubbler to draw water through a sponge. The intake flow is not strong and the odds of a small goldfish being suck into it is very low. It is ideal for use in a breeding tank with goldfish fry. It’s an adequate biological filter when used in a small tank but is limited in how successful it is as a mechanical filter.
Box Filter: It is also inexpensive, low maintenance and works like a sponge filter by using an air bubbler and can be filled with whatever filtration media you like. It works best in a small to medium sized tank since it is limited in its effectiveness as a mechanical and biological filter. Also good for small goldfish fry
Internal Power Filter: The internal power filter uses an electric centrifugal pump to draw water through its filter media. These aquarium filters create better water circulation, better mechanical and biological filtration than the sponge and box filters. This type of mechanical filtration work best on 10 to 90 gallon tanks but can be used in combination with other filters in larger tanks. Depending on how strong the water circulation that is created by the outflow of the aquarium filter, it might not be ideal for weak swimming fancy goldfish or small goldfish. By turning the outflow towards the wall or creating a baffle to slow the water down, it will allow your fancy and small goldfish to live in that goldfish tank. Using aquarium decoration like plastic plants or a rock acts as a good diffuser of a strong water current.
Hang On Tank Filter: A hang on tank filter hangs on to the back of the tank and works like the internal power filter. Some use disposable canisters so it doesn’t act as a good biological filter. Models with the optional Bio-Wheel provide a good biological filter. The water that falls back into the goldfish aquarium agates and adds more oxygen into the water.
External Canister Filter: A external canister filter Works in the same way the internal power filter works but sits outside of the goldfish aquarium in a self contained pressurized canister. These filters are slightly more costly and require more maintenance than the previous aquarium filters discussed but offer a high level of mechanical and biological filtration. External canister filters can be hidden from sight and won’t take up any space in your goldfish tank.
Under Gravel Filter: It draws water down through the substrate and traps the waste particles in the substrate. The gravel substrate acts as a large mechanical and biological filter but more maintenance is required in the form of vacuuming the gravel to remove accumulating waste that adds to the bioload. This is not a good filtration solution if you have rooted aquatic plants in your goldfish tank. Reverse under gravel systems work backwards by taking water in from the aquarium water, running it through a filter and forcing it up through the gravel substrate. This system helps keeps the substrate free of excessive dirt and waste.
Sump Filter: These are often home made and costly but work as a good filtration system. By running the goldfish aquarium water through a tank hidden below that is filled with filter media, you can not only create a large mechanical and biological but increase the water volume of the entire system. The increased volume of water is great for a higher stocked goldfish tank. Any heaters can instead be placed into that sump pump filter tank as well.
Trickle Filter (wet/dry): Is a great biological filter and perfect for higher stocked goldfish tanks. It works by spraying water over the surface of the filter media, creating a flow of highly oxygenated water through the filter media; prime conditions for beneficial bacteria growth.
Selecting an aquarium filter will takes some research on your part and a good start is to read product reviews made by actual users of these mechanical filters. Just remember that fancy goldfish like the: veiltail, telescope, bubble eye, lionhead, ranchu, celestial and a few other goldfish breeds don’t do well in strong flowing currents.