Unfortunately not a lot, including the water
and the microorganisms that we have
become so accustomed to. Most decorations
and the gravel in your freshwater tank have
to go. Crushed coral, sand, or a bare-bottom
tank are the best choices for a marine tank.
Live rock is your best bet for decorations,
but we’ll touch on that soon.
Let’s first examine some of the other parts
that can be switched over. Many heaters
work for both fresh and salt aquariums.
Just make sure the heater is made for both,
but chances are it is. Know that depending
on the temperature of your home and how
intense your lighting will be, you might
not even need a heater. Lots of filters, in
particular powerheads, make the switch
as well, but for safety reasons you need to
make sure that the manufacturers intended
these filters for both fresh and salt, just as
you did with the heaters. Two of the three
basic filter ideas still work: mechanical
filtration, to trap particulate matter; and
chemical filtration, which can chemically
remove pollutants. The big change of
mentality here is the third filtration tier, the
biological. There’s still waste to be removed,
and the wastes are actually the same ones
(ammonia, nitrite, nitrate, phosphate, etc.),
but they are dealt with quite differently in
the marine aquarium.
Possibly the nicest thing about salt water
is how it is a different density than fresh
water. While it does reduce the amount of
oxygen dissolved in the water, it also makes
waste products lighter relative to the water.
What’s so great about that? Well, in fresh
water, waste goes everywhere, especially
to the bottom of the tank. In a marine tank
The modest-yet-expensive foundation to biological filtration and decoration of any marine tank
should be cured live rock.
you can capture waste before it starts to
enter the nitrogen cycle, which cuts back
on the need for water changes. This is a
huge benefit, considering you have to pay
for the salt and sometimes even the water
when you do water changes.
So how do you grab this waste before
it starts decomposing? With a protein
skimmer. You need a high-quality protein