What kind of filter do I need for a
saltwater aquarium?
There are two primary methods
for filtering a saltwater system.
Method 1:Used for reef tanks, but also very
effective with saltwater fish tanks
Live rock for microbial filtration (home for nitrifying
bacteria) and a skimmer to remove excess protein. Often in
this setup, aquarists will make use of a filter sock in the sump
to perform macro-filtration and remove excess particulate matter
from the water.
Some people utilize a refugium system to supplement their
filtration. Refugiums take many forms, but essentially consist of a sump with
a sand/mud base (such as Miracle Mud) with live rock, macro algae,
and a light. Refugiums are very effective, but are not
commonly used by the novice reef keeper. If you are
interested in knowing more about how to set up a refugium,
NorthSide's expert staff can help you.
Method 2: Used primarily for fish only
systems
Bio-chamber, or wet/dry trickle filter system, which utilizes
bio-balls in the sump as the area for nitrifying bacteria to
colonize. Wet/dry filters are often topped with a tray
where filter floss can be used to perform macro-filtration.
A skimmer is also needed in fish only systems to remove excess
protein from the water.
How much live rock do I
need?
NorthSide recommends a minimum of 1 pound of live rock per
gallon of water to provide adequate filtration, but you may
exceed this minimum recommendation. The more live rock,
the better, providing that you still have adequate flow in your
tank. Be sure that your powerheads move water in all
areas of the tank if you choose to have a significant amount of
live rock.
Depending on the density of the rock, 1 lb per gallon may or may
not provide you with enough rock to make a nice aquascape.
Either select at least some live rock that is very open in
structure or consider adding some dry lace rock to round out
your aquascape.
Lace rock comes from the ground and is usually purchased dry.
However, NorthSide periodically seeds lace rock in its live rock
vat. "Seeding" is the process of exposing dry, lifeless
rock to an environment rich in bacteria and other live rock
critters that slowly make their way to the lace rock.
After several weeks in an aquarium or live rock vat full of
other live rock, lace rock becomes "live" and may be counted
toward the minimum 1 lb per gallon rule in setting up one's
aquarium.
Using some lace rock also makes for a cheaper setup in a
saltwater aquarium, because lace rock costs about 1/5th the
price of live rock. This is one corner that NorthSide says
can be cut in trying to make a saltwater tank more affordable in
the setup phase. We caution, however, that people using
lace rock need to be more patient in their tank setup because
lace rock cannot be counted as "live" for several weeks and does
not contribute to reducing ammonia until it has been well
colonized by nitrifying bacteria.
What is meant by "cured"
and "uncured" live rock? How do I know the live rock I am
buying is cured?
Live rock is kept moist, but not totally submerged during
shipping and arrives to our store with many of the life forms
still alive. Be aware however, that live rock must
be cured before you can put it in an aquarium that already has
fish and invertebrates in it.
Curing is the process of
waiting for organisms on the live rock that did not survive
shipping to die and fully decompose. This process involves
very high levels of ammonia and is best done at our store.
It is possible to start an aquarium with uncured live rock;
however, there is no real benefit by curing the rock yourself.
Additionally, you must put up with the rotten egg smell it
produces.
There are two things you should do to
determine if your live rock is cured. First, ask the store
when they got the live rock in. In a very well established
system with excellent skimming ability, it takes about 1.5-3
weeks to cure a piece of rock. This also varies depending
on the density of the rock, how much cured rock is in the vat
with it, how much
filtration is on the system, and how much flow is moving through
the rock.
The second thing you should do to
determine if the rock you want is cured is to smell it.
Cured rock has a very musty, earth-like scent to it. If
the rock smells like rotten eggs, put it back and come back in a
few days.
Do not believe someone who
tells you that they just got in cured rock. It takes a few
days for it to smell bad and unethical vendors might try to push
it out the door before they should. Likewise, "cured" rock
purchased on the internet may be cured, but if it is not shipped
TOTALLY submerged in water, you will have to cure it yourself.
These vendors are very rare, mostly because it is
cost-prohibitive to ship rock fully submerged due to the weight.
Can I use an undergravel filter
with my saltwater aquarium?
Generally undergravel
filters are no longer used in saltwater systems. While
this was the practice 15+ years ago in saltwater, the hobby has
since developed more effective filtration methods.
How
important is a sump?
The sump is the center of all complete saltwater filter systems. Using a filter pad or a filter sock can trap waste from the water as it enters the sump from the overflow above. We recommend purchasing the largest sump that will fit in your aquarium stand. Having extra space in your sump makes it easier to maintain your aquarium. Filter systems using in-sump protein skimmers and/ or submersible pumps require larger sumps than systems with in-line (external) pumps and hang-on or in-line protein skimmers. If you have room, you may place pieces of live rock in the sump to act as additional biological filtration.
How does biological
filtration work?
Biological filters work by growing bacteria, which break down fish
wastes. Nitrosamonas and Nitrobacter break down
ammonia, which is very toxic in alkaline water, to nitrites.
Nitrites are then broken down to nitrates, which are much less
toxic. Nitrates are removed by water changes.
What is a plenum? What does
it do? Is it good or bad or indifferent for a saltwater
aquarium?
A plenum is a form of biological substrate filtration that
lies under the substrate that removes organic contaminants such
as nitrate. The general consensus is that plenums are very
sensitive and become unbalanced very easily. Their usefulness is
often regarded as dubious.
NorthSide has worked on a number of systems with plenums and it
is our opinion that although they might help remove nitrates
from an aquarium, the risk of having one greatly outweighs
potential possible benefits. Nitrates may be removed from
the water above, but the contents of the plenum are extremely
noxious and dangerous to the aquarium's inhabitants.
NorthSide has been called to numerous homes to attempt to rescue
fish and coral from tanks that have very suddenly taken a turn
for the worse. What we typically find are very smelly
aquariums with dead or dying corals and fish that have "nuked"
within about 24 hours of the owners having suspected there was a
problem. By the time we get a call, it is usually too late
for most of the fish and coral.
The cause? A slightly disturbed plenum. Either a
sand sifting critter or human has created a small hole in the
plenum that has allowed sulfur dioxide to leach out in to the
aquarium. In a single word, the result is devastating.
Can I use a canister filter on my saltwater aquarium?
Yes. You may choose to use a canister filter if you wish.
There is no harm in doing this if you maintain it regularly.
Canister filters help serve as a method of macro filtration, and
can help to polish the water, making it clearer. In reef
tanks, the fine pad may be omitted to allow very small desirable
particulate matter to reach the live corals.
That being said, we do not consider canister filters to be a
required part of a saltwater tank. The most important form of filtration for a saltwater system should be provided
either live rock or a wet-dry filter in the sump.
I am setting up a fish only
saltwater system. I am confused about whether or not I
should use live rock or a wet-dry system for biological
filtration. Could you tell me the difference? Also,
do I need a canister filter for a fish only system?
Wet-dry filters do an excellent
job of breaking down organically produced ammonia and
nitrite. They also drive off carbon dioxide and add oxygen
to the aquarium.
Live rock may replace the function of the bio balls used in a
wet-dry system. Live rock produces less nitrates, which is the
only downside of a wet-dry or trickle system. Live rock,
however, does not handle the same amount of organic waste that a
wet-dry filter does. For this reason, live rock alone may not be
suitable for a heavily stocked fish only aquarium, unless
the aquarium has a very strong protein skimmer.
Canister filters do a better job of removing
particulate matter than a wet-dry filter alone. For a fish only
tank they remove fish waste and
inorganic particulate matter. Changing the filter pads
regularly disposes of these materials. In addition, canister
filters provide supplemental biological filtration
and a small degree of circulation. You may choose to
add a canister filter if you wish.
Subscribe to our weekly newsletter via
email detailing our specials and current inventory.
