The AquaClear line consists of hang-on-back (HOB) filters in different sizes that simply hang over the edge of the aquarium, eliminating the need for hoses and space beneath the aquarium to house an external filter. They are a perfect solution for beginners and those short on space. The filters are also extremely economical, ranging from just $22 for a Mini which is rated up to 20 gallons to $65 for a monster 500 which can handle up to 110 gallons all by itself.
The system works by pulling water up through an intake tube via an impeller and pushing it through the filter media and back into the tank via an overflow lip. The media is where the AquaClear filters really shine. Unlike other HOB filters that use cartridges, AquaClear media is held in an easy to remove insert, but each set of media (biological, chemical, mechanical) is it's own individual unit, wrapped up in a mesh bag and stacked one on top of the other. This makes it very easy to clean and prevents shock to the aquarium since you can replace the media one at a time, allowing the bacterial colonies to propogate from the old media to the new. It also spreads out the media over a greater area, allowing longer contact times and improving efficiency. Using your own media is possible, though not as convenient as in a canister filter. The set-up also allows for easy restarts, since the distance the impeller has to pull the water is minimal. All is needed is to fill the filter with water and the impeller will do the rest. The filter also allows the flow to be adjusted by simply shifting the intake tube to the side of the impeller. This is handy during feeding times when you don't want the filter's flow to create a blizzard of food flakes. The lack of tubing and the ever-annoying suction cups (ever done battle with a suction cup inside your tank that just doesn't want to let go?) also makes it very easy to move this filter from one tank to another, making it an excellent choice for a quarantine tank filter or a seeding filter to jumpstart the bacterial colonies in a new tank.
The quality of the plastic used in the filters is a little questionable, but unless you routinely abuse your filter equipment with heavy objects or like to leave it out on the floor to step on, it's not a big deal. The only other qualm users might have is the waterfall style outflow. This can get quite noisy depending on your water level (unless you enjoy the noise of splashing water) and for those of you with CO2 injection of some sort, the water disturbance will cause a lot of CO2 to escape.
If you're looking for a cheap, basic filter that is dependable and convenient, AquaClear filters are definitely a best buy, earning five out of five fish.
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