It may seem odd to find a plumbing section in a book on aquariums. This is, in fact, not so. Around reef tanks a lot of pseudo and real plumbing often needs to be done, and experience tells me that many hobbyists are not very familiar with the many different types of fittings and valves that are used in this pursuit. Moreover, there are so many of them that a little more information on the types frequently used around reef tanks, will hopefully help quite a few readers.

As the aquarium gets more elaborate in the number of components that make up the filtration system, more and more types of fittings need to be used to make the system safe and prevent back siphoning, while at the same time allowing for an easy adjustment of the flow.

Hard piping a system, meaning using PVC or some similar type of pipe, is the most durable way of installing a tank. It is usually also the one that will look the most professionally finished. There is, however, nothing wrong with using flexible hose. If you decide on the latter, do not use the cheaper variety of hose, rather invest a little more and use flexible PVC (sometimes referred to by one of its brand names: Tygon).

PVC is used by plumbers, pool installers, and so on, and local building and construction regulations set the safety and materials standards that such pipe must meet. Because different types of installations require different types of pipe, PVC pipe can be bought in various grades known as "schedules".

The most commonly used schedule is schedule 40, often referred to as "sched 40". It is also the least expensive. Usually sched 40 pipe is white. In some areas of the country, however, and in Canada, sched 40 is gray. The next schedule offered for sale is sched 80, a type of pipe that is usually gray, and has a thicker wall making it better for high pressure applications. It is not necessary to use sched 80 around reef tanks because we do not run reef tank systems at high pressures. Yet a sturdier variety, called sched 120, is available as well. It also has no applications in the hobby.

Although the outside dimensions of any size pipe in schedules 40, 80 and 120 is the same,the inside diameter diminishes as the schedule number increases. For example, 1 inch schedule 40 has a larger inside diameter than 1 inch schedule 80, which in turn is larger than 1 inch schedule 120.

Besides schedules 40, 80, and 120, you may come across thin wall pipe referred to as SDR pipe. Such pipe is excellent for use around reef tanks as well, but it is more expensive than regular schedule 40. If, however, you want to use gray pipe, and you do not want to pay the higher price of schedule 80, or CPVC pipe, use SDR.

CPVC, as opposed to PVC, is another form of pipe, made mostly for higher temperature and higher pressure installations. We do not need such pipe around reef tanks.

To be complete we should mention that you can also obtain clear PVC pipe, but at a considerably higher price. Besides the ones already mentioned, special application type pipe is available as well, mostly in highly sophisticated materials. As you probably already guessed, such pipe will be very expensive. Who uses this pipe? More often than not it is used for food grade applications (for example polysulfone) or for the transport of strong chemicals (for example polypropylene).

7.1.1 COUPLING:

A fitting used to connect two pieces of pipe of the same size. The pipes to be connected slide into the fitting, one on each side. Put some PVC primer and glue on all pieces first, push them together, give both a quarter inch turn, wipe off the excess glue with a rag, hold firmly together for a few seconds, and the two pieces of pipe are now permanently one.

Couplings are not usually necessary in short pipe runs, but come in handy if you have a number of leftover pieces that you would like to use rather than throw out.

Couplings also come in threaded variety, in which case you will need the matching fittings as well. Male adapter fittings have their threads on the outside, female adapter fittings have them on the inside.

Sometimes you will measure the length of a piece of pipe that you need to make a connection, cut it, or saw it, and make a mistake. If the piece is too long, you can always cut off a short bit. But if it is too short, you must either throw it out and cut another piece of the right length, or you can make it longer by using a coupling.

7.1.2 ELL OR ELBOW 90 DEG,45 DEG, 22.5 DEG:

These fittings are used to make 90 deg, respectively 45 deg or 22.5 deg angled turns with pipe. They are available in slip (no threads on the inside) or threaded. Slip is sometimes called socket/weld as well.

Elbows are perhaps the most frequently used fitting when plumbing an aquarium, indeed, because of the limited amount of space underneath the tank, many bends usually have to be made.

90 deg and 45 deg elbows are easy to find at plumbing suppliers and are stocked by many hardware stores as well. 22.5 deg elbows are not as common. If you think you may need them, you would be wise to have them ordered in advance for you.

Of course, if you run out of 90 deg elbows, and you need to make such a turn in the pipe, you can always use two 45 deg, or four 22.5 deg ones. The end result may not look as good, but it will do the trick.

7.1.3 TEE-FITTING:

Tee-fittings, also called tee-connectors, or just Tees, are used to split one line up into several. The most commonly used Tee is the 3 way Tee, allowing you to split one line up into two lines, something that is often necessary around the aquarium. Four-way Tees are also available and allow you to split 1 line up 3 ways. In all cases, one end is used for the input, and the others for the outputs.

Tee-fittings are, amongst others, often used for:

• Splitting up a water line into several lines, e.g. as with two water returns to the tank.
• Making a bypass around filters, for example around an in-line micron filter, or around a Fin-L-Filter.
• Making an extra water line available off the main one to run a protein skimmer.
• Making extra lines available to pipe to reactors, e.g. for carbon dioxide, and oxygen.

NetPets® Main Page

contact information Main Reference Library

The Fish Center