Stones can greatly benefit backyard ponds, especially when they are placed on the bottom. The best types of stones are river pebbles which are rounded, as they make an ideal medium. However, there are a number of things you should consider prior to adding them.
Why River Pebbles Are The Stones Of Choice
River pebbles come in various sizes and are widely available at home improvement shops and any outlet that specializes in rocks and soil. These pebbles have beautiful, natural colors and complement the surrounding landscape. They can be costly when sold in bags, but the best deals can be gained by purchasing directly from a source that distributes them.
River stones don’t cover a whole lot of space, especially when they are purchased in a forty pound bag. This is why when using them as a pond medium you will want to purchase in bulk from someone that specializes in big orders. However, it is essential for the stones to be washed before adding them to your pond, because they might have been previously exposed to salt, non-conducive minerals or contaminants which can compromise your water quality.
How River Pebbles Influence Pond Bacteria
Beneficial bacteria can bring tremendous advantages to any pond in which they are present. They actually thrive when river pebbles are present, especially those which are about four inches. This is because the bacteria react better to these stones than they do to sand, and plants will also root in them with greater ease.
There are disadvantages to incorporating these stones however. For one, they can be challenging to clean, especially when sludge builds up. The reason for this is because sludge acts as waste which is organic, that collects as time passes. It will usually consist of things such as leaves, sticks, plants and branches. Every pond will develop sludge at some point, but there are a number of hassle free ways to deal with it.
Sharp And Large Stones
Contrary to popular belief, not every river pebble is completely rounded. Some have sharpened edges, which can damage the pond liner if they come into contact with it. As such, it is best to avoid adding stones which have sharp edges. Larger stones can be used, given they have rounded edges and have been sterilized beforehand. Some pond owners have placed larger stones with jagged edges near their pond’s shoreline, only to have it fall in. Not only can it be a headache to move (especially if the stone is heavy), but this increases the risk of damaging the liner. Flagstone is the best option as it doesn’t become easily disconnected.
The best bottom medium for a pond is a combination of river pebbles with soil that is sandy. You will also want to use the pebbles near the spillway and overflow, filling them up to the level of the water. This is very important in areas that receive lots of rain, as any excess water will be filtered via the pebbles without washing away the smaller fish.