:  Equipment
Once you have considered the types of animals you want, you will want to research the types of equipment that will be needed to house them. Each component is available from a number of different manufacturers. Each manufacturer produces variations of every piece of equipment. You will need to talk with other aquarists and your local fish store about equipment before you make your purchases. The system parts fall into 3 general categories. They either hold the bulk of the water, light the water, or cleanse and move the water.

Parts that hold the water:
  1. Aquarium: ranging in size from a few gallon into the hundreds, aquariums are by no means standard. The two basic aquariums are made of either glass or acrylic.
  2. Stand: ranging from wrought iron to wood, the stand has to be tough and able to support an enormous amount of weight.
  3. Cover: from simple plastic or glass sheets to elaborate hoods, this keeps the water and fish in and people (most) out.
Parts that light the aquarium:
  1. Lighting and Hood
Parts that move and cleanse water:
Filtration refers to the cleansing of water by some type chemical or physical means. There are many types of filtration systems available today that were not available 30 years ago.
All filters perform some or all of the following tasks:
  1. Mechanical filtration is the entrapment of debris from a water system. It usually employs some type of floss or pad material that catches objects as water passes through, much like a furnace air filter in a home.
  2. Chemical filtration is the use of chemical bonding to remove substances from water. Iron oxide is use to remove phosphorus from aquarium systems this way. Activated carbon is used to remove organic compounds from water in this way also.
  3. Biological filtration is the growth of beneficial nitrogen-cycling bacteria that process nitrogen in aquarium systems to prevent it from killing livestock.
  4. Sterilization involves the use of high energy light or oxidizing agents to improve the quality of a water system.
Different types of filtration options perform one or more of these tasks. Each system tends to perform one of the tasks best. Mechanical and biological filtration are essential to the day-to-day operation of marine life of any saltwater aquarium. Chemical and sterilization techniques are useful in short-use cycles and as optional methods for treating specific problems.

Mechanical and Biological Filtration Options:
  1. The Undergravel Filter is a 50+ year old filter option that some aquarists still use. This method is losing popularity because of better options that are now available. It was once considered the most important part of the filtration system of any setup.
  2. Internal filters have a limited role, especially in hospital and quarantine tanks where very little biomass is present so little filtration is needed.
  3. External filters are used by some aquarists for their ease of cleaning and quiet operation. They are clean and simple to operate.
  4. Sump filtration systems use a separate aquarium to filter water. The water is passed through pads that screen debris, barriers that churn and oxygenate water, and often live rock or sand that help biologically filter the water.
  5. Refugiums are a modification of the sump concept to enhance the biological filtration capacity. They employ the use of algae and even plants (mangroves) under lights in a sump aquarium. Live sand and mud is employed to help biologically and physically filter aquarium water.
  6. Live rock and sand are now used in sumps and aquaria to enhance biological filtration. Old marine systems employed lifeless decorator rock to enhance aquarium appearance and add refuges for animals. Today, rock is removed from rubble systems, washed (hopefully), and sold to aquarists for both aesthetics and biological filtration.
  7. Fluidized-bed filters are rather new types of filters that increase the surface area for the growth of beneficial bacteria. A fine granular material is suspended in a filter canister which allows microbes to grow and process nitrogen.
Chemical Filtration Options:
  1. Activated carbon is used to remove suspended organic compounds from water. This is often used in short-term interventions when suspended organic material is in excess.
  2. Ion exchange devices work to chemically remove specific types of solutes from marine aquarium water. Resins bind to specific molecules such as nitrate or phosphate and remove them from solution. The resin beads are housed in nylon or polyester bags that are simple to remove from a mechanical filtration device. These devices are used in deionization filters that convert tap water to water safe for use in a marine aquarium.
  3. Poly filters employ pads to remove toxic compounds from the aquarium water. The pads change color as they become loaded with compounds, indicating the end of the media life.
  4. Protein skimmers rely on the chemistry of lipids and proteins to remove them water solutions. They originated over 40 years ago but have only gained popularity in the last 15 years. They are considered an essential component of any competent marine system.
Sterilization Options:
  1. Ozone is an oxidizing agent that releases oxygen as it reacts with organic material. As an oxidizing agent it is safe for use in marine systems, and really helps to clarify water.
  2. Ultraviolet sterilizers destroy microbes with high energy light. They have gained popularity in recent years but should only serve as an accessory to an already well-designed filtration system.