The two basic forms of plumbing found in most saltwater aquariums, hard plumbing, and soft plumbing, both have their pros and cons. Hard plumbing begins with the easier of the two plumbing systems; hard-line or PVC. This can be mixed with a variety of different plastics, resins, and caulk to create the various products that make up a typical aquarium setup.
PVC can be mixed with rubber, nylon, or other flexible tubing to make it strong and durable for use as plumbing. This is the bulkhead and drain pipe combination that you see in most aquariums. The bulkhead connects the aquarium to the rest of the plumbing system using the flexible tubing and it is located in the aquarium on the top of the bulkhead. The drain pipe connects the bulkhead to a drain pan below it.
There are a number of different pumps that can be used in an aquarium. There is the two-stage system that requires a larger than normal water flow rate in order to accomplish the task at hand. In some aquariums this two stage pump is actually under the water; this makes it unnecessary to have the bulkhead for the water return pump. The tank and sump portion of the aquarium just contains the sump basin and the replacement water for the aquarium water. There is also a single stage pump available that works on lower water flow rates. These are often used in aquariums that do not get very high volume water flows.
Pipes for aquariums range in diameter, length, and material. The most common materials are copper, plastic, polyethylene, rubber, nylon, and brass. The diameter of the pipe that is used will depend on how much of the aquarium water movement is needed to be pushed through the pipe. For small aquariums that only house one fish or a few plants a narrower pipe will be sufficient. For larger aquariums with multiple fish and plants the need for a wider pipe is advisable.
PVC tubing is another option for aquariums. It is made from either plastic or vinyl. Although plastic is the most common material PVC tubing comes in a variety of colors and styles. When purchasing PVC tubing it is always best to purchase the same size of tubing that is used in a display tank to ensure correct water flow.
Another type of pump for an aquarium is the aquarium reef pump. A reef tank is an acrylic or glass panel that is placed above or alongside an aquarium to provide an environment similar to that of a coral reef. Reef tanks provide a good environment for corals to flourish, grow and breed under the optimum lighting conditions that exist in their natural habitat. One of the most popular pumps for reef tanks is the bubblers or bubbles pump. These are generally used with reef fish as they create a bubble stream effect that is beneficial to the fish and reduces the evaporation of water from the fish.
In an aquarium with a sump it is usual to have a sump pump installed as well. In this case the water pump will pump the aquarium water through a water filter system to the sump. The sump pump is designed to continuously filter out any debris that may have entered the aquarium as well as providing constant water temperature. There are designs where the entire unit is located above the aquarium and in this case the water is pumped into the aquarium via a piping system. Whatever the design of the aquarium system it is important to have a backup sump just in case of a power failure.
If you do not use a sump for an aquarium then the water in the tank will continually enter the display tank through an exit hole. As the water enters the display tank the water will be pumped back into the sump so it can be reconditioned. If you are using a sump then it is important to set the correct pressure for your tank. For example, the pressure should be ten pounds per gallon.