MT HELENA POOL TO POND CONVERSION

The owners here had tried simply switching the pool off to attempt the simplest approach to pool to pond conversions, which sometimes works in humid East Coast cities like Sydney & Brisbane, but just doesn’t work here in Perth in our Mediterranean type climate with hot dry summers and cool wet winters.

So they decided to follow the Aquascape ecosystem approach with an external upflow wetland filter pond powered by a very low energy pump (~75W for 12KL/hour) teamed with pond habitat of rock, gravel & waterplants placed inside the pool shell in the deep end.

It is a big deep solid concrete pool so there was plenty of room to place rocks to create underwater habitat for fish and still leave plenty of room for swimming and snorkelling. The shallow end has been left as the existing plastered pool shell, giving this pool to pond conversion a bit of a Jekyll and Hyde combination of being a rock pool and conventional pool.

They have since added a serious variety of freshwater fish, marron etc and even some native eels! They are breeding like crazy in an absolutely thriving freshwater ecosystem. The wetland filter pond acts as a nursery areas for the babies before they make their way down into the main pool .

Yes there is a bit of algae and debris buildup in this pool which the owners have chosen to keep currently as it’s providing a lot of breeding habitat and protection for their huge variety of fish. The exposed pool shell and rocks could be vacuumed using the pre-existing conventional pool pump vacuum system, but right now the owners want the fish population growth to continue and are happy to live with the algae for now.

Type of water feature & Size

Concrete pool to swimming pond conversion. We built an ~10m2 upflow wetland filter and placed a total of 16 tons of moss rock in the pool and wetland filter edging. Our deep-end rock work rose up from the pool floor to join with the existing pool edging rocks and the overhang feature waterfall. We’re pretty happy with the way it all joined together and looks like it all belongs together.

Estimated current build cost 2025

~$40k for large wetland filter and underwater pond habitat including 16 tons of moss rock