Pond Aquaponics

For some people, aquaponics should be aesthetically pleasing and resemble a natural ecosystem as much as possible. It should blend in with their landscaping and not be intrusive. Some people don’t like the idea of growing fish in large tanks believing they look too much like a factory rather than a relaxed garden feature to their backyard. They may also be vegetarians who are naturally reluctant or squeamish about killing their own fish that over the months have grown into a loved pet!

Geoff Lawton standing on the deck touches a Koi in an Aquaponics pond

This is where pondponics comes into its own as more people people are reinventing the shape and form of conventional aquaponic system designs to better blend in with their urban needs. Les Mulder’s aquaponics system is a small garden ornamental pool with a lovely little waterfall that is positioned just off his deck.


What better place to enjoy an early morning breakfast and watch the Koi fish and various goldfish lazily swim about. The main business end of his aquaponics system feature a collection of Murray Hallam growbed tanks which are hidden from view in that long narrow space many backyards have – the unproductive space between the side of the house and the boundary fence. Except here there are strawberries growing in a Nutrient Film Technique channel that is bolted to the side of the house. The growbeds provide all the salad greens and herbs needed for the family.

All powered by Koi in the Goldfish pond. Les Mulder shows us his aquaponics system

At the far end are two olive barrels that have been transformed jnto biofilters. What is the purpose of the biofilters? Les explains that fish water containing fish solids needs to be filtered out from clogging the system grow beds by providing bacteria to multiply and convert the waste into the necessary Nitrates or plant food.

A DIY Biofilter made from an Olive barrel

The biofilters are really nothing more than a barrel stuffed with heaps of onion bags. These plastic onion bags when knotted make an excellent nook and crannies for bacteria and solids to collect and adhere to. Eventually when the barrels fill up with fish waste  Рthey can be deposited into the vegetable garden as nutrients. The bacteria grow and multiply in the biofilters and process the waste water returning it sparkling clean to the plant grow beds and finally back to the Koi pond.

A wonderful little system that uses little energy and provides oxygen for the fish and vegetables for the kitchen.


One of the main media used in Aquaponics is Hydroton a small round clay ball. Hydroton is quiet expensive to buy per bag. A solution is to use crushed red roof titles that can be purchased from a recycle centres. The crushed media once sifted is perfect as a growing media for aquaponics. This system was designed and built by Charles Bacon of Ecolicious.