The Best Koi Pond Liners - Know Your Choices

It is necessary to use a pond liner to prevent the pond water from seeping into the surrounding soil. There are several types available: concrete, fiberglass, rigid plastic and flexible plastic liners. Each one has advantages and disadvantages, so you need to understand each one and decide what is more applicable to your particular pond.

Concrete pond liners last a very long time. If you want to go for a really permanent pond, use concrete. However, one of the problems usually encountered with concrete liners is that they tend to leak toxins into the water. They are also more expensive.

Fiberglass pond liners have a lifespan of more or less 50 years. They are easy to install and expand for ice and do not crack. One disadvantage is that they look less natural and are hard to disguise.
Rigid plastic pond liners are the cheapest. They can look natural and tend to be resistant to sharp roots or rocks. One disadvantage, however, is the difficulty in installing them. It can be hard to get just the right size hole to lay the liner in and stop leaks and drainage. It is a good choice in warmer climates.
Flexible pond liners have typical lifespan of 20 years. They are resistant to weathering and cracking in the cold and heat. They are non-toxic and inexpensive. This type is good in any climate and, because of its flexibility, is easy to install.

There are some basics steps you must do before installing your pond liner. First, decide where you want to place the pond (see above) and outline the shape and size with a marker like chalk or colored string. Next, start digging the hole at least 3 inches outside of the line. If you are planning to dig a hole deeper than 3 feet you might need to get a permit. Remember, the side of the pond should slope in about 20° from the vertical.

Following this, you will need to fill the bottom with sand and salt to delay unwanted growth and make the bottom more level. I also recommend the use of a liner underlayment. This will help protect the liner form tree roots and other objects that could puncture the liner when its filled with water. Then you put the liner in and fill with water. This task actually requires a little work to get it right. However, it is important and necessary.