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Written by Leon Huang
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Tuesday, 26 July 2005 |
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Page 5 of 9
Hang-on-back(HOB) filters
As its name suggests, this filter hangs onto the back wall of the fish tank. With the filter itself outside the fish tank.
Most of such filters' filtration media comes in the form of slot-in cartridges.
How it works
An intake tube extends into the fish tank's water. And a impeller motor
inside the filter pulls water up the tube, where the water then passes
through the filter cartridges, and back out into the fish tank in the
form of a mini waterfall.
"The filter is capable of all three forms of
filtration: Biological, Mechanical, and Chemical."
Pros
Being external and its slot-in cartridge design, makes this filter very
easy to clean and maintain. All you have to do is open up its top
cover, pull out the cartridges, and briefly rinse it in old fish tank
water. And if the cartridges get too worn out, simply throw them away
and slot in a new one.
HOB filters that are not too small, will usually have two cartridge
slots. This allows for one biological cartridge and one carbonized foam
cartridge. Which makes the filter capable of all three forms of
filtration: Biological, Mechanical, and Chemical.
And if you do not fancy the cartridges that comes with the filter,
simply pack it with your own filtration media. HOB filters' size are
usually large enough to pack a decent amount of media into it.
And finally, for those who enjoys watching waterfalls, this filter is a must-have!
Cons
The slot-in cartridges are convenient to change, but they cost quite a
bit more than the normal filtration media. For the same price as a
carbonized foam cartridge, you can probably purchase enough generic
carbonized foam pads to last you 3 to 5 times longer.
Noise is also an issue for this filter, as the waterfall does create
quite a bit of splashing sound. And the lesser the water in your fish
tank, the harder the water splashes, the louder it gets.
And finally, this filter will require space behind the fish tank to fit itself in.
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