Back to Nature

By | May 25, 2016

Jane Griffiths converted her chlorine pool into a natural wetland, using plants to filter and clean the water.

water-lilies

When we moved into our house, there was a sparkling blue pool. After the first summer storm, it instantly turned green. So began an ongoing battle involving pool testers and endless visits to the pool shop to have the water assessed, which usually resulted in adding chemicals with scary warnings.

When the pipes developed yet another leak, we covered it up and there it remained for three or four years. Until Tosca arrived.

A cute package of fur that was white, who shortly spotted the pup-sized puddle in the centre of the pool covering. It took her about two seconds to bite on her way through the netting. It was very cute while she was a pup – but we had visions of Tosca drowning and 30kg of fully grown German shepherd began wearing the edges of the cover.

The pool was uncovered by us immediately. And the thought of an all-natural pool began to germinate.

How a Wetland Pool Functions

hotel-swimming-pool

Water is circulated by means of a pump between the swimming area of a wetland and the pool. The wetland with creatures, its plants and substrate, filters the water, returning it. The water needs to circulate constantly to keep beneficial organisms alive, but as a lower wattage pump than that of a swimming pool does this, much less electricity is used and all compounds that are dangerous are eliminated.

The Design

Our pool was a standard rectangle, a thing I’ve never liked, as all the shapes in my garden are natural and flowing. Instead of dividing the pool (the way most conversions are done) I wanted a deep splash pool inspired by rock pools with a wide step for lounging in the water and flat rocks to bask on. It was a daunting task and I decided to call in an expert. Architect Anthony Philbrick of wetland POOLS built his first wetland pool in 2007 for his four-year-old daughter. He has since built more than 200 wetland pools, perfecting the art of using nature to purify the water. With his imaginative architect brain, he jumped at the opportunity to build something different.

He suggested an elliptically-shaped pool rising out of the shallow end with a seat running around the inside. Water would flow from the ellipse, over a waterfall and into the wetland, which would lie in the remaining area of the pool. This would completely change the shape of the old pool resulting in a new and exciting space.

How We Did

water

The pool was emptied, all cracks were fixed and the surface sealed. In the shallow end, the outer walls of the ellipse were built using bricks with the inner step made with concrete and bricks. In its centre, the ellipse is 1,8m deep, ideal for dunking. It was plastered, sealed and the exterior clad in Latitude Tile & Decor Autumn cladding to give the impression of a stacked stone pool rising out of the water. Larger pieces of the same stone were laid on top of the ellipse.

Gravel was added to one-half of the remaining area of the existing pool. Using sand bags filled with gravel, a bank was built to retain the gravel on one side. This produced different levels ranging from the original depth of the deep end to a few centimetres deep, providing environments for various wetland plants.

Suction pipes were laid under the gravel and a 200W high-flow submersible pump was installed inside a barrel and buried just under the gravel. This sucks the water through the wetland and pumps the clean water into the ellipse in a continual cycle. Stepping stones, plants and fish were added.

The Result

On the very first evening after we filled the pool, a frog began croaking, the first I have ever heard in my garden. Although the water was murky in the beginning, within a few weeks it cleared. After a month, it was crystal clear and has remained so ever since. The only maintenance required is to trim back the plants, occasionally vacuum the swimming area and top up the water.

Although we swim far more often than before, it’s become much more than a swimming pool. Everyday birds splash in the pool or use the papyrus fronds to make nests. Damselflies and dragonflies dart above the surface and bees sip water from the moist rocks. In addition to the ever-changing textures and colours of the wetland plants, I’m now experimenting with edible water plants.

A previously sterile area of my garden has been revitalised by reconnecting it to nature. And Tosca now has a dog-sized pool to play in.

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