How to install preform ponds in your garden

Build a pond 1   2   3   4   5   6   7   8  

Preformed fibreglass ponds

The alternative to working with a flexible liner is using fibreglass preform ponds supplied in many shapes & sizes.

Check carefully before purchase for:

  • Shelf variety and the proportion of deep water to shallow shelf area.
  • Wildlife pond - Choose a shelf layout that has wider shelves for plants and shelves at different depths for variety of habitats for wildlife.
  • Fish pond - Choose preform shape with more deep area and less planting shelf.
  • Always measure your chosen space before going to the Garden Centre. It is easy to be misled by size when looking at an empty pond out of situ.
  • Choose the largest pond your space will allow.

Fitting preform ponds into the ground:

  • Often more tricky than you think.
  • Mark out the profile of the pond and its shelves on the ground using a series of hose pipes or string.
  • Measure the depth of each level.
  • Dig a hole a little larger but as near as possible to the correct shape so that the preform sits snugly in the hole.
  • Protect the preform pond from sharp stones with a layer of geotextile in the hole.
  • Bed the pond into the hole so that it is level.
  • Start to fill with water and place a spirit level over the top edge.
  • As the water starts to weigh down the pond correct the level if necessary by backfilling the space around the preform shape with sand.
  • Preform ponds have a horizontal rim around the top which is difficult to hide or camouflage into the garden.
  • Water can only fill to just below that rounded top edge or the water will flow away.
  • The only way to hide that rim is to securely fit slightly overhanging stones or coping slabs.

Preform ponds can also work well if placed inside a raised pond surround of concrete blocks. The horizontal rim can then be hidden under a securely fitted coping stone.