
The subject of pipe fittings is confusing and sizes vary depending on where you live
Why Are Fittings Needed?
In almost any pond you have at least 2 components that need connecting and in some cases more than 3 items of equipment. Most connections start with the pump.
There is a vast variety of pumps for ponds and many these days come with fittings that make life a lot easier.
- Hozelock Cascade Fountain or Titan Waterfall pumps
- Oase – make a wide variety of pumps for fountains, waterfalls, filters, and specialized applications
- Fish Mate – also make a good range of pond filter and waterfall pumps
More often than not the pipe from the pump needs to change direction and the important thing to remember here is to use a fitting with a smooth bend. By using smooth bend curves you conserve pumping power. Every pump loses a bit of flow for every fitting included in the line and the more abrupt the change in direction, then the more flow is lost … this is due to what is called pressure drop.

If you need to split the flow into 2 directions avoid “T” pieces as shown to the left. Based upon what was said in the previous paragraph you’ll see that one of the directional changes of the fitting is at 90 degrees. This kind of split creates a relatively high-pressure drop that translates into lower flow. You’ll find that there are many sizes of pipe fittings and the golden rule is always to choose the widest diameter fitting you can … once again the reason is to lower pressure drop and therefore minimize the amount of flow that will be lost. A “Y” piece is a much better way to split the flow into 2 directions.
When you use a “Y” piece to split flow then this minimizes friction losses or pressure drop in the fitting. Note the inlet side is of a wider diameter than the outlet and that the 2 outlets have what are called “stepped” fittings. The idea of the stepped fitting is to make it easier to attach the same fitting to different pipe diameters.

Whenever you use any type of stepped fitting attach to the largest diameter pipe you can … and then cut off the smaller steps so that they do not impede water flow through the pipe and fitting. Some “Y” fittings have valves built into them so that you can control the flow … maybe you want more in one particular direction than another.

Which is the best pipe to use?
Algae will grow on the inside of pipes and therefore it is best to reduce this growth by using opaque plastic pipe that does not allow algae to grow so quickly for the reason that sunlight cannot penetrate the pipe.
Very often you’ll want to bend the pipe and this is the second reason transparent pipe is normally not the best choice. Ribbed flexible pipe is by far the best and is perfect for pond keepers… when you bend this kind of pipe it does not kink and act as a restriction to water flow. Most transparent plastic pipes kink very easily and the impact is a lower water flow to your waterfall or fountain.
All pipe whichever type you use should be the shortest possible length and the widest possible diameter consistent with the rest of your equipment and the fittings you use. By optimizing these 2 choices your pump will perform at its best.
When you attach pipe you’ll often use what we call Jubilee Clips if you do use these then try to use stainless steel clips otherwise they have a habit of corroding and being impossible to undo some years down the track