The Aquarium Principle


All too often we hear people talking about balance. Balance your work and personal life, balance your diet and exercise. It seems that everything around us is about balance.

And what happens when we can’t balance all these things? That’s right, we experience instability where things don’t quite work. This is especially true of the natural environment where plants and animals have evolved over millennia to be in balance with one another.

My view on balance was something I learned at a young age.

My first incidental experience of environmental balance was on my 8th birthday when Mum and Dad bought me a giant 4-ft fish tank. As a kid I was obsessed with animals, insects, birds and reptiles. It was time to learn about the world of aquatics and about ‘balance’. The balance of an ecosystem; the good and the bad.

I call this form of balance ‘The Aquarium Principle'.

 Fish keeping has entirely changed my perspective on the world around me and I apply this principle to everything I do as a Landscape Architect.

I want you to imagine that an aquarium is a little planet Earth. Think of those complex systems that are working to create balance in a forest. Think about how trees work. They absorb carbon dioxide and turn it into oxygen and filter nutrients that are absorbed into the soil. Trees provide homes and food for all the weird and wonderful life forms that exist around us. They are an essential component for the health of this world. We already know how removing an element disturbs the balance and causes major problems. We know that to live on Earth we need sunlight, oxygen and water. Plants, insects and animals to use these to live and to die and thus create a cycle.

An aquarium will need to have the same set of rules if we are to play Mother Nature. I did not play by the rules of nature when I started my new endeavour. I had a sterile tank with tap water, rocks, a plastic plant, a ‘No Fishing’ sign and lots of fish. The only thing I did have right was a light and a filter. I was heartbroken when Zeebs, Speckle and Goldie number 10 did not swim for long. They floated, and the water was making my room stink.

But I never gave up. I so desperately wanted an aquarium like the one on my fish food tin! So I wandered down to the creek that runs through our beautiful rural property. I looked at the clean water, listened to the songs of insects and frogs and observed the schools of fish swimming in water where the sun had warmed the surface. I realised that if it worked here then I must use the things from the creek in my aquarium.

I had started to play by the rules.

I brought home some plants, soil, snails and popped it all in. What I didn’t know was at the micro level that I was also bringing in healthy thriving bacteria. Just like we know that yoghurt provides our stomachs with good bacteria, this also is the case with water whereby bacteria break down and feed on waste products. I popped it all in and I had my first successful tank. The snails ate the algae, the plants absorbed the waste, the fish ate the plants, the bacteria broke down the waste for the plants to absorb and so on.

But a closed system does eventually build up with waste. This is when balance or ‘The Aquarium Principle’ comes into play, for my balance became un-balanced and my tank, my mini ‘World’, collapsed. I had too much waste and not enough waste-absorbing life forms.

But with the failures I did not give up because I was obsessed. So obsessed I ended up working at an aquarium when I was 16. By the time I was 18 I had 15 4-ft tanks around the house, when I announced I was going to University my Dad said “Good! Take your tanks with you.” I took 3, and even got a job at another aquarium whilst at University and I even started a business at Uni where I set up and created environments in aquariums.

Through the years I learned about water. The different types, the quality, the chemistry and the science behind healthy water and how to maintain it. I learned about the different varieties of plants suited to the type of aquarium you want, about all the different types of fish species and how they can be used in different ways to keep your tank healthy.

I got so good at aquarium keeping that my mini worlds did not need a water change for 9 months. The only thing I needed to do was feed the fish and top up the evaporated water. By creating bacteria-rich water, the bacteria helped break down the waste during the nitrogen cycle.

I had learned how to create a balanced system.

All the species of plants I had selected had different roles in absorbing waste and cleaning the water. The various fish species also had different roles. From the bottom-dwelling catfish cleaning up the mess and eating the algae to the middle-dwelling fish who create all the mess but would clean up and tidy the tank and plants and the top-dwelling fish who would skim the top of the water in search of debris and remaining food.

Everything in the tank had a role and if I was to remove one of these essential components the tank would change. Sometimes it would change and create its own balance but if it was something too essential, then everything would crash. If I put too many fish in, they would eat all the plants, then there would be too much waste for the plants to absorb and then the ammonia levels would become toxic and create a disaster. I can go through so many examples of how the balance could be slightly altered and would usually end in failure. This is ‘The Aquarium Principle’.

This principle works in the same way as it does on Earth.

You can apply it to your garden, to the row of street trees, parks, forests and even your home. If you do not have the essential components to support and maintain life then your world starts to crash. If you create a garden with plants that do not belong to your area then they won’t survive unless you tend to them. They won’t provide food to benefit local animals and the animals that live in that area will move away, which then causes other disturbances to the balance.

Native animals

Micro bats are a good example of this. Extensive works around Melbourne’s waterways and the clearing of trees and habitats have led to the decline of this species. An individual Micro bat can consume up to 600 mosquitoes in one night. When you have your BBQ and you get bitten by these pesky insects, think about how those little bats could have helped you out.

Exotic plants

The rows of London Plane trees in Melbourne’s CBD are also an issue. Have you ever wondered the impact that exotic trees have on natural balance? Australia is a country which has created its own balance over hundreds of millions of years. Plane trees are deciduous. In its native environment the leaves that fall would provide nutrients to understory plants that would thrive during the only time light penetrates the floor. So what happens to all these leaves in Melbourne? They end up in the storm water drains, or polluting machines have to go into the city every day to sweep them up. These leaves which are nutrient-rich are now a waste product. As we learned from the fish tank, waste products that are not absorbed by another plant can become a problem.

And what about its impact on bio diversity? Non-native trees negatively impact native plants and animals. We also know that the Plane tree's tiny pollen spores increase hay fever and allergies. The list goes on and on.

This is why we need to address issues of imbalance and make sure to implement strategies that don’t negatively impact our ecosystems.

So next time you notice something isn't working in your outdoor space, step back and take a moment to understand why this might be. Something within your area is most likely unbalanced and you may be able to pinpoint what it is and implement a change to fix the problem.

‘The Aquarium Principle’ has become a rule in all my design methods.

It ties in well with my mission to conserve nature, educate people, promote sustainable designs, look after our local environments and reduce the most pressing threats to the diversity of life on Earth. This is what I am all about and I love being a Landscape Architect.