Allotment Articles 2.
Choosing And Installing A
Fish ponds can be made from many different materials but none are as versatile as a pond liner. They come either pre cut in boxes in a wide range of sizes, or some retailers sell them off the roll and cut to any length you require. There are 3 distinctly different types of materials that liners can be made from;
1 - PVC
2 - Polyethylene
3 - Butyl Rubber
PVC liners only carry a 5 year guarantee as a rule and can be expected, with care, to last about 10 years. Polyethylene is the same material that dustbin liners are made from but of course pool liners are much thicker. This material has the advantage over PVC that it stretches considerably so is far more difficult to puncture and is UV stabilized so it doesn't go brittle in the same way PVC will. The guarantee on this material is up to 25 years. Butyl Rubber liners also stretch and don't perish but because they have been around successfully for longer their guarantee can be up to 50 years. The length of guarantee on a pool liner is reflected in its price with PVC being the cheapest and Butyl the dearest. The serious enthusiast has always favored butyl liners, but PVC liners are very popular with first time buyers.
Whichever liner you choose they have several advantages over a pre-formed pool. Firstly you can have the pool almost whatever shape and size that you want. Secondly after you have chosen the size, you choose the type of liner to suit your budget and thirdly, if it does get the odd puncture, repair kits are very cheap. The main disadvantage with a liner is of course if a dog jumps in, its claws may well puncture the liner in scores of places making it impossible to repair, whereas a pre- formed pool will stand up to this sort of abuse.
After you have bought the liner you need to dig the hole to the size of the liner. Do remember to allow extra liner for the depth and for edging off around the pool.
To measure a hole for a liner, measure the length and breadth and then add double the depth to each measurement. Finally add another foot, or 30 cm for finishing off around the sides. When actually digging the hole, shelve the sides so that it goes down in steps. The first shallow shelf will be for marginal plants and the deeper ones for lilies and lily like aquatics. Shape the hole so that it has smooth curves in it as this will enable the liner to be installed with less creases and folds. Then when the hole is finished, line it with something soft. Packs of special protective material can be bought, or else things like soft sand or old carpet and curtains can be used. This will protect the liner from any stones that may work their way to the surface. Finally put your liner loosely in the hole and carefully position it so that it overlaps all around. Many people wrongly believe that a liner should be positioned over the whole and then filled with water to stretch it into the shape of the hole. This is not how it should be done because liners do not stretch that much. Also it should not be stretched at this stage because this will take the life out of it and may prevent it from being able to stretch and take up a new shape when the soil underneath it moves over time. Finally, fill the liner with water and trim and finish edging the sides with rocks and plants, or whatever to conceal the edges of the liner. After this the pool is ready for fish and plants to be added to bring it to life.