This Swell Nano Sponge Filter is our smallest filter, with a miniature sponge that provides just enough mechanical and biological filtration for a temporary hospital tank, or a small tank with a very low bio load. It also comes with a built-in air stone that'll keep your aquarium aerated with a fine stream of bubbles.This Swell Nano Sponge Filter is quick and easy to install. Before you place it inside your aquarium, attach the airline provided to the narrow spout in the middle of the filter. Then, use the suction cup provided to attach the filter to an inside surface. After that, attach the other ends of the airline to an air pump. If you've done all that correctly, you should start to see a fine stream of bubbles rising out of the top of the filter. Now all that's left to worry about is keeping it clean. To do that, remove it from your aquarium and give the tiny sponge a little squeeze in a bucket of tank water (or dechlorinated water). This will remove a lot of the trapped debris that may have built up in the sponge. Be careful not to clean your filter in regular tap water, the chlorine, chloramines and trace heavy metals may kill your colony of beneficial bacteria.A filter is an essential piece of equipment for all aquariums. They do a lot of the heavy lifting in your underwater ecosystem, removing waste from your water column while also providing a home for a large colony of beneficial bacteria. This bacteria breaks down the waste picked up by the filter and, in doing so, keeps your water clean.There are many different types of filter. Some, like this Swell Nano Sponge Filter, are only suitable for tiny aquariums and temporary hospital tanks. Other filters, like external canister filters, are specially designed for large aquariums with a high water volume. If you have a tiny tank, then this Swell Mini Aquarium Filter is ideal. If you have a large or medium-sized tank, then check out our range of internal filters and external filters.