Freshwater

Figure 6-1:
A power
filter draws
water in,
passes it
through
charcoal,
and returns
it to the
tank.
A power filter hangs on the back of an aquarium and sucks up tank water
through an intake tube, which hangs inside the aquarium. The water passes
over the filter pads and filter media (which house biological colonies that
provide biological filtration) and then returns to the water surface. The charcoal
in the pads work as chemical filters, and the fibers pick up debris before
it clogs the media.
Clean the pads on these filters by rinsing them with dechlorinated water and
replace them every month so that you have fresh charcoal. Unfortunately,
replacing the pads destroys the biological colony, but there is enough
remaining in the aquarium and other parts of the filter to repopulate quickly.
Some power filters contain bio-wheels, which rotate so that they come into
contact with both the water and beneficial oxygen in the air, and never really
need to be replaced unless they break. This wheel keeps the bacteria colony
alive even if you change the internal pad. Bio-wheels combos are the best
type of power filters to buy.
You can use power filters in any type of system.
Powerheads
Chapter 6: Equipment and Other Technical Stuff
A powerhead is a cool piece of equipment that isn’t really classified as a filter,
but it can help increase an undergravel filter’s output and efficiency by drawing
water up through the tubes at a faster rate than most air pumps with attached
airstones can. A powerhead is nothing more than an electric motor-driven
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