The Box fish tank filter is ideal for small aquariums and fish bowls. One filter is suitable for a 10 gallon (or smaller) tank. They are basic plastic boxes fitted with a perforated lid and a lift tube. The tube connects to an air hose, and the bubbles rise up the tube from the bottom. Media is packed into the box. Water flows down through the media and up the tube. The bubbles help to aerate the tank.
Canister filters are external fish tank filters. The perfect solution for a large aquarium where a strong water current and a high level of filtration is necessary. These include supplementary media such as carbon. External filters also contain a greater amount of sponge and biological media, enhancing the level of mechanical filtration and breakdown of ammonia. Canister filters have an integral water pump.
Chemical reactors or aquarium reactors are chambers in which aquarium water reacts with some medium to alter the water chemistry, either adding substances to the water or removing them. These filters are designed to increase the contact time between the water and the surface area of the media.
Two common examples are calcium and phosphate reactors.
Outside Filters are very common. Also known as hang-on-back (HOB) filter because that is often where they sit. These filters provide excellent mechanical and biological filtration. They are ideal for use in tanks where space is limited inside the tank, and they mean that there is no need for a filter to be seen inside the tank. They use a pump to suck water up a tube from the aquarium. The water then flows through a series of media compartments with various types of media and back into the tank via an overflow. These filters are available in a full range of sizes.
Protein skimmers are used in saltwater tanks to remove substances before they begin to break down. Water is pumped through a tall vertical column in which air bubbles are rising. The basic principle here is to get air bubbles into contact with the tank water. The idea is that polluting substances are attracted to the air bubble. These concentrate in the bubble stream, rising with it and appearing at the top as foam. The foam is collected and the water flows back into the tank.
A sponge fish tank filter is usually as simple as a sponge attached to a riser tube. Water is drawn through the sponge and out the other end of the tube. Simply connect the unit with an air pump airline tubing and provide both aeration and filtration for your fish. These filters are perfect for Fry Betta Shrimp tanks, and they are easily cleaned by gently squeezing the sponge in a bucket of tank water.
Trickle or wet-dry filters drip or spray aquarium water over a medium for marine and freshwater aquariums. This maximizes oxygen saturation and provides excellent biofiltration. The filter box is placed on top of the aquarium. These units are extremely efficient at converting ammonia to nitrate. They provide a large surface area for beneficial bacteria colonies to grow.