Nano Tank Filtration
In setting up our nano reefs, we have three considerations for filtration, similar to FW if that is where you started. The three components are mechanical, biological and chemical. If you are new to SW, than a new incredible natural method for filtration is used, called live rock. Live rock you ask??? Read on:
Mechanical
This is provided by sponges, bioballs, ceramic beads, biowheels, and other components of filters (canister, hangon, etc,) However, they can turn out to be nitrate traps if meticulous cleaning in aquarium water is not done on a routine basis. They do their jobs too well in a sense and the cleaned out material gets trapped and converted into nitrates which are far more deadly in SW tanks compared to FW. Many in the nano-reef community will tell you to forgo filters, although in many small tanks, some people will use a hang on the back (HOB), like an AquaClear, and use that for water flow and holding filter media. Some even make small refugiums out of them. Another option some people use is a small amount of filter floss with frequent changes, often 1-2X per week.
Chemical
Although many testing kits are pretty sensitive, not all will detect low levels of certain chemicals such as phosphates in a color that can be seen by the eye. Most nano-reefers will include media inserts to assist in chemical filtration. Inserts that are quite popular include Chemi-Pure, Purigen, and phosphate binders (SeaGel, PhosGuard, Phosban). Activated carbon can be used though some people tout ChemiPure to be better (no supportive evidence). ChemiPure is purportedly a combination of activated carbon and resin. Some have concerns about pure carbon claiming it can remove vital elements from the water (no studies to support this). If you do use them, make sure to rinse them out thoroughly before putting them in your tank.
Biological
Ahh...the big difference now between FW tanks and SW. The predominant source of biologic filtration is live rock. The rock isn't alive, of course, but it's many interstices fill up with the bacteria so familiar to those of us who started out in the FW biz (i.e., with our sponges and gravel). Denitrification can occur here as well as in the substrate. In addition, the live rock is home to many animals that help keep the tank clean. This is the magic of how marine tanks, which were difficult to support, became more easy to maintain and 'overthrew' the undergravel filter. In order for the live rock to do it's job, however, it needs to have good flow to circulate the water over the rock, hence the need for water circulation. Your substrate will also contribute to filtration, to follow.
Water Circulation
I've added this here because water circulation is extremely important in a marine tank's filtration setup including nano tanks. It keeps water flowing by and thru the live rock. It also will carry food to your corals (should you decide to do up a reef) and carry wastes away from them. This is provided by a type of water pump called a powerhead. Recommendations for flow are 10 X the water volume of your tank per hour as a minimum. Another 'rule of thumb' some people say is 10X good, 15X, better, 20X or more best. Higher flow is most important if you plan to keep corals. You want to avoid positioning your pump in a manner that might overcome your fish or disturb the substrate. Many powerheads/pumps come with intake grates to keep detritus and fish out. I suggest you use some protection over the intake.
Summary
With tank your tank selected, your nano's filtration system will consist of:
1) live rock and substrate
2) powerheads for circulation (HOB filter if you plan a refugium or place for inserts)
3) filter media
SH
In setting up our nano reefs, we have three considerations for filtration, similar to FW if that is where you started. The three components are mechanical, biological and chemical. If you are new to SW, than a new incredible natural method for filtration is used, called live rock. Live rock you ask??? Read on:
Mechanical
This is provided by sponges, bioballs, ceramic beads, biowheels, and other components of filters (canister, hangon, etc,) However, they can turn out to be nitrate traps if meticulous cleaning in aquarium water is not done on a routine basis. They do their jobs too well in a sense and the cleaned out material gets trapped and converted into nitrates which are far more deadly in SW tanks compared to FW. Many in the nano-reef community will tell you to forgo filters, although in many small tanks, some people will use a hang on the back (HOB), like an AquaClear, and use that for water flow and holding filter media. Some even make small refugiums out of them. Another option some people use is a small amount of filter floss with frequent changes, often 1-2X per week.
Chemical
Although many testing kits are pretty sensitive, not all will detect low levels of certain chemicals such as phosphates in a color that can be seen by the eye. Most nano-reefers will include media inserts to assist in chemical filtration. Inserts that are quite popular include Chemi-Pure, Purigen, and phosphate binders (SeaGel, PhosGuard, Phosban). Activated carbon can be used though some people tout ChemiPure to be better (no supportive evidence). ChemiPure is purportedly a combination of activated carbon and resin. Some have concerns about pure carbon claiming it can remove vital elements from the water (no studies to support this). If you do use them, make sure to rinse them out thoroughly before putting them in your tank.
Biological
Ahh...the big difference now between FW tanks and SW. The predominant source of biologic filtration is live rock. The rock isn't alive, of course, but it's many interstices fill up with the bacteria so familiar to those of us who started out in the FW biz (i.e., with our sponges and gravel). Denitrification can occur here as well as in the substrate. In addition, the live rock is home to many animals that help keep the tank clean. This is the magic of how marine tanks, which were difficult to support, became more easy to maintain and 'overthrew' the undergravel filter. In order for the live rock to do it's job, however, it needs to have good flow to circulate the water over the rock, hence the need for water circulation. Your substrate will also contribute to filtration, to follow.
Water Circulation
I've added this here because water circulation is extremely important in a marine tank's filtration setup including nano tanks. It keeps water flowing by and thru the live rock. It also will carry food to your corals (should you decide to do up a reef) and carry wastes away from them. This is provided by a type of water pump called a powerhead. Recommendations for flow are 10 X the water volume of your tank per hour as a minimum. Another 'rule of thumb' some people say is 10X good, 15X, better, 20X or more best. Higher flow is most important if you plan to keep corals. You want to avoid positioning your pump in a manner that might overcome your fish or disturb the substrate. Many powerheads/pumps come with intake grates to keep detritus and fish out. I suggest you use some protection over the intake.
Summary
With tank your tank selected, your nano's filtration system will consist of:
1) live rock and substrate
2) powerheads for circulation (HOB filter if you plan a refugium or place for inserts)
3) filter media
SH