A bulkhead is a plumbing part used to mate a container with pvc pipe. By using a bulkhead you can drill a hole in your sump and/or tank and still have a water tight seal. In other words, bulkheads allow you to connect two comparments so that you can pass water through them, without letting water seep around the joint.

The bulkhead pictured here is an Oceanic brand bulkhead that will cost you about $15 at your LFS. I personally think that buying one is foolish when you can make one yourself for less than $2.00. As you can see in this picture, a bulkhead consists of three parts: a threaded male piece, a threaded ring (female), and a gasket. To make your own, all you need is a male bushing, a female bushing, and a gasket.

The gasket will cost about $1.16 and the two PVC pieces run about 35¢. You may want to purchase two gaskets, but I only ever use one. To install the bulkhead you will need to drill a hole in the container just large enough for the male bushing to slip in. Drilling through glass requires a special drill bit (not sure which because I always have my LFS drill it for me, but you could either buy the bit or have a glass maker drill it.) Place the gasket on the side of the male bushing and slip the male bushing through the gasket and through the drilled hole. Now wrap the threads of the male bushing with plumbing tape and then screw the female bushing on. Its best not to use PVC glue because this joint could never be undone and its not necessary. The gasket and the plubming tape will ensure that the joint is water tight. You will need to use glue to fasten the PVC pipes to the bushings because these are slip-type joints and not threaded.

An alternative method to the type of bulkhead I have just described would be to use bushings that don't have threads. These you would have to glue, however. I prefer the threaded type bushings because the joint can always be redone if you need to change anything later. □