Aquarium Filters Buyers Guide

Information on Aquarium Filters and How To Buy the Best Aquarium Filters.

An aquarium filter is an essential component of any aquarium system. This device is designed to filter the water to remove uneaten food, fish wastes, and other debris. There is a wide range of filter options available, varying both in their design and in the type of debris they are able to remove from the water. Without a filter, the water in the aquarium will soon grow dirty and cloudy, negatively impacting the health of your fish.

Aquarium Filters Guide - Table of Contents

• 1 Aquarium Filters Product Types
  • 1.1 Mechanical Filters or Sponge Filters
  • 1.2 Undergravel Filter
  • 1.3 Power Filters
  • 1.4 Canister Filter
  • 1.5 Chemical Filters
  • 1.6 Protein Skimmer
• 2 Aquarium Filters Key Features
• 3 Aquarium Filters Product Advice
• 4 Aquarium Filters Buying Tips
• 5 Popular Aquarium Filter Brands
• 6 Aquarium Filters Glossary
• 7 See Also

Mechanical Filters or Sponge Filters

These filters work by forcing water through a plastic container holding a sponge material designed to filter solid debris from the water. Mechanical filtration is a process similar to straining the water. While it removes solid debris, dissolved water contaminants are able to pass through the filter. This filter will need to be supplemented with frequent water monitoring and routine water changes to remove harmful water contaminants such as ammonia. Most often found on small aquariums, this is the least expensive option, but it is not very powerful. The air pump on a mechanical filter may not be strong enough to pull in water from a medium or large-sized aquarium. However, this style of aquarium filter is ideal for tanks intended for breeding, since the filter will not suck in baby fish.

Undergravel Filter

An undergravel filter is among the most popular biological filters, which is designed to breed bacteria that will eat waste products present in the water, such as ammonia and nitrites. The undergravel filter is a plastic grate fitted to the bottom of the aquarium, underneath the gravel or sand. A small vacuum pulls water to the bottom of the tank. As it is filtered by the gravel, the debris is broken down by the bacteria that are already present in a healthy aquarium environment. This style of filter requires the use of a gravel vacuum to remove leftover debris. While they are a popular option for small aquariums or for those with live plants that could be sucked in to a filter that utilizes a pump, some fishkeepers find that undergravel filters let the aquarium water grow dirty faster than other filter styles.

Power Filters

Another style of biological filter, the power filter, is a popular choice for mid-sized aquariums, between ten and 75 gallons. These filters may hang on the back of the tank, known as an HOB filter, or remain submerged inside the tank. HOB filters often pour the water back into the tank in an attractive waterfall-style. Internal filters, meanwhile, are attached with suction cups to the interior surface of the aquarium. The filter holds a foam sleeve or plastic tray filled with a filtration media. The pump forces water through this filter before returning it to the water. There are many sizes of power filters available, rated by the number of gallons. Be sure to select a power filter capable of handling the volume of water in your aquarium. If the power filter is rated for a tank size that is smaller than your aquarium, it will not be able to efficiently clean the tank.

Canister Filter

This style is the most advanced type of filtration system found on home aquariums. Ideal for medium or large tanks with more than 30 gallons of water, the canister filter is contained in a separate system that sits outside of the aquarium, either on the floor next to the tank or on the aquarium stand. The canister filter box holds up to eight different types of filtration system. The benefit of this method is that the filter can be customized to the particular needs of your aquarium environment. Two hoses connect the canister filter box to the aquarium to pump water back and forth.

Canister filters are the most expensive option available to aquarists, but they are the most efficient option for larger aquariums, especially those with many fish or with several large and exotic fish that can be extremely sensitive to water quality changes. Canister filters should not be used with small fish, which could get sucked into the filter. Also, the canister filter unit itself will require maintenance, similarly to the aquarium.

Chemical Filters

Many of the above filtration systems include chemical filters, which use activated carbon to reduce odor and make the water appear cleaner, as part of the filtration media. Activated carbon soaks up chemicals and minerals, and can even make clean water look even clearer. On the other hand, there are also chemicals that act by themselves as chemical filters. A few drops of these chemicals in the water can perform some cleaning, but they are no substitute for an actual filter setup on the aquarium. Chemicals alone will not keep the water healthy for your fish.

Protein Skimmer

Available in several forms, this filter is mainly used on saltwater setups. This piece of equipment removes dissolved organic material from the water, drastically reducing the chances of a complete die off of the fish in a saltwater tank.

Size of Aquarium
The size of your aquarium should be your main concern when buying an aquarium filter. Some filters can only efficiently remove contaminants from an aquarium under five gallons, whileothers can handle a display aquarium with hundreds of gallons of water. Many aquarium styles are rated for a specific size of aquarium.

Type of Filtration
Some filters only remove solid debris, while others are more effective at removing dissolved water contaminants. In addition, your fish may need specific types of filtration to conform with their water quality requirements. For example, the typical goldfish requires very little filtration, while a very large saltwater tank needs specialized filtration such as a protein skimmer to avoid the death of exotic and expensive saltwater fish.

Type of Water Treated
Many aquarium filters can be used on both freshwater and saltwater aquariums, but not all. Saltwater will ruin some filters designed only for freshwater environments. If you have a saltwater aquarium, be sure to find a filtration system that is designed for operation in this environment.

No matter the size of your aquarium or type of fish, you need an aquarium filter. The filter serves to remove solid particles as well as harmful water contaminants, such as ammonia, which can affect the health of your fish. While purchasing a filtration system is necessary, it does not negate the need for regular water changes to ensure that the water provides a clean environment for the aquarium inhabitants.