In the world of water features , there are two types of ponds: ponds with rock bottoms and ponds with liner bottoms. In my line of work and from my own experience of having ponds, my personal and professional opinion sides with those that ROCK! Not only do ponds with rock bottoms look more natural, but they carry additional benefits as well.
Installing a pond brings a soothing essence to a landscape. It creates a unique ambience that simply cannot be established with an array of beautiful flowers and lush greenery. A pond breathes life into its surroundings. To fashion such a natural creation, rocks and gravel are essential. They simply can make the difference between a “This was built by a professional” look, to a “You can tell they built that by themselves and had no idea what they were doing” look. If you know what I mean? Blending rocks and gravel into a pond is one of the most basic yet most important parts of construction. This step is what brings the feature to life.
Many debate that “rocking” a pond is not necessary, but the benefits speak for themselves. Rocks and gravel not only bring a natural cosmetic element, but also provide assistance with maintaining a healthy ecosystem. By creating a vast area for beneficial bacteria to grow on, the rocks aid in filtration. The gravel also provides a place for any sediment to fall and stay . Like a fish tank that has small pebbles, ponds with gravel provide a space for any small debris to reside, “no floaters” so to speak.
The rocks and gravel not only have the job of aiding in filtration, but they also protect the liner. Due to harmful UV rays, the sun can be damaging to a pond’s liner. If there is no barrier from the sun, the liner can become brittle on the edges making it susceptible to tears and cracking. Rocks and gravel provide this barrier and can preserve the condition of a good liner for many years. I have seen pond liners that were 15 years old that were shaded by rock and were in great shape. I have also seen a 4 year old pond liner from a pond that was not rocked in and the liner was in horrible condition. The rocks can make a big difference.
When choosing rocks and gravel for pond construction, it is important to think about a few details. The size of the gravel is important for its functionality. It should be 1 ¼ inch. If you go smaller with a ⅜ inch size gravel, it may actually work against you. The sediment will not fall into the gravel but will settle on top creating a dirty exterior. As for the type of rock, river gravel works the best for supporting a healthy ecosystem. Make sure to stay away from anything that carries a high level of calcium, this includes limestone. Being from Indiana, limestone is readily available, but the high levels of calcium in the rock is not healthy for a pond. It can lead to algae growth, and let’s face it, nobody wants to deal with algae!
Now, lets talk big rocks! The larger boulders are for creating the natural look of your pond. It is important to choose a variation in size and shape to build a perfect balance that works just for your pond. These structural boulders are the foundation to your feature. They act to support the sides of the pond keeping the walls and shelves from caving in. Although the liner may seem like it is secure, the large rocks actually help to keep the liner in its place. Rocks really do serve a vital role in pond construction.
As you can see, rocks and gravel are more than just cosmetic. They really do promote a healthy ecosystem. Having a pond with a rock bottom is not only easy of the eyes, but is more likely to make the maintenance less draining on the owner. This why we like ponds that ROCK!