Natural Pool Conversion at the Green Power House

In June 2008 I joined a small group of like-minded specialists to convert a suburban house in Linden into a sustainable green home called “The Green Power House”.My task was to convert the existing chlorinated pool into a natural swimming pool.  The objective was to harmonise the pool within the landscaped garden and for it to operate without any chemicals as well as to be energy efficient.The original pool had a grey marbelite finish and was constructed as a semi-above ground pool with the upper walls serving as a seating area.

 Original pool

 The pool was drained and ideas formulated.  The client had requested a wetland and pond feature to be created near the pool. We decided to incorporate this feature into the wetland pool concept as space was limited.

 Ideas?

  Natural swimming pools or wetland pools need efficient filtration in order to keep water sparkling clean and safe to swim.  In a conventional chlorinated pool, water is circulated through a sand filter and kept clean using chlorine.

 In a wetland pool, water is circulated through a wetland where naturally occurring micro-organisms recycle and purify the water.  Ideally the wetland needs to be half the surface area of the pool and at least fifty percent of the wetland should be filled with bog plants for effective bio-filtration of wastes.

 Inner landscaped wall

 We decided to construct an inner wall within the pool to create an additional wetland area for water lilies and other submerged plants.  The design of the wall followed on the curves of the landscaped garden.  We raised the floor of this inner wetland area by backfilling with building waste and after compaction we poured a concrete floor.

 Raised floor

 At the top end of the garden a wetland was excavated and a concrete lining constructed.  The concrete was sealed with a waterproof application.

 Excavation of wetland

 Wetland sealed and waterproofed

Once completed the landscaper created the wetland using wetland plants best suited for colour, variety and decorative interest.

Landscaping wetland

 Circulation and aeration are important within any wetland pool and water needs to circulate continuously for the plants' roots to cleanse the pool effectively.  By moving water through a waterfall or fountain air is introduced into the pond which provides a habitat for aerobic bacteria.  These bacteria are responsible for keeping the water clean and clear.

 During the construction phase of the inner wall, a drain was installed at the deep end, to efficiently remove ammonium and other organic wastes from the bottom of the pool.  Water from this drain is passed through the original sand filter and enters the pool again via the wetland.

Aeration of this pool was created by using a series of flowforms.  Due to their unique design, water is aerated and cleansed as it passes from one flowform to another.

 Flowforms

 Flowforms are beautiful landscape features

 We installed an ultraviolet light system as they are very effective against floating algae, and also eliminate potentially harmful pathogens.

 Ultraviolet light system

 The pool was filled with municipal water and the wetland filled with plants.  Once the water had stabilised we introduced natural micro-organisms to manage the ecosystem.

 Water lilies

 Wetland

 Wetland and pool

 Chemical-free pool

 Open day at The Green Power House

 Make-over!

 In September 2009, we revamped the wetland pool.  Water lilies and other submerged aquatic plants where unable to propagate within the walled-in section of the pool due to water movement.  We decided to move the beautifully established wetland plants from the upper wetland into the walled-in section of the pool.  Water lilies were moved into the upper wetland where there is less water movement.

 Revamped pool

 Revamped wetland