Fish Pond Liners Explained

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Written By Mark Washburn

Mark has 20 years of experience as a professional pond management consultant.

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If you’re looking to either build a fish pond or have a pond installed, there’s a very high likelihood that you’ll be using a pond liner of some kind in the construction. Granted some ponds are actually formed out of concrete but most water features will use some sort of liner.

Pond liners definitely make pond building much easier. Particularly for the diy projects they’ll save time and a lot of frustration. When researching liners you’ll find that they come in either preformed or prefabricated designs, which are made out of a rigid molded plastic as well as thin rubber sheets which are more flexible to work with.

Choosing the best pond liner for your needs really depends on the type of pond you’re wanting to build. What we’re referring to is the size and overall shape and configuration your wanting to create.

Preformed Ponds

Preformed ponds make it very easy and simple for anyone to install a nice looking pond. There should probably be more emphasis on the simple part as digging is not always that easy. Nevertheless, a pvc plastic prefab pond liner allows for an easy installation. A hole needs to be cleared that matches the shape and form of the liner. Fill in any spaces or gaps under the shell to support it and you’re done.

Because they’re rigid, preformed liners don’t offer the same degree of customizations as a rubber liner might, but many people don’t necessarily need that. If one’s pond design is very small, say under 300 gallons, then a prefabricated pond liner will work great. As the pond size and gallon capacity goes up, many people begin to transition over to rubber sheets.

EPDM Pond Liners

EPDM stands for (ethylene propylene diene Monomer (M-class)) which is a synthetic form of rubber. You’ll find it used in a variety of machines and applications but for pond owners it’s primary qualities are durability, it’s resistance to heat and cold, and overall weather proof capability.

Most epdm pond liners will have a warranty for an effective life span (Firestone pond liners for example are expected to last for 20 years). This warranty may not include damage from accidental punctures, but it’s ability to not crack or wear with age should last that long. Rubber liners have a distinct advantage over the plastic varieties because they are extremely versatile to work with. They can be laid in virtually any shape, depth, or configuration without any problems.

Rubber liners are normally offered in several different widths of rubber. These are listed as 45mil and 60 mil with the latter gauge being a bit more durable. In terms of the overall size (length and width, there really are very few limits. Most rolled liners can be found up to 50′ wide and 100′ long. For larger installations several rolls can be bonded together.

Larger and more complex ponds always use epdm rubber liners but you’ll also find them commonly installed in small Koi and fish ponds as well. They have proven to be safe for fish and wildlife. It is possible to put rocks and stones on top of these liners however it’s important to use rounded or flat stones and avoid anything with sharp points or edges.

A Note About Cleaning Your Pond Liner

Whenever you find the need to clean a pond, it’s a good idea to clean some of the liner if you can get at it. For a hard shell liner you can pretty much scrub these aggressively without any problems. A rubber pond liner will require a bit more care. Avoid using harsh solvents of any kind and use light pressure when scrubbing or brushing.

When a pond is built using high qualities materials and you’ve followed the recommendations from the manufacturer, there’s a very good chance that your pond (and this includes pond liners) will provide you with many years of trouble-free service and enjoyment.

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