Carnivorous Pitcher Plant

Carnivorous Pitcher Plant
one of the first plants in our swim pond

Sunday, 17 April 2011


Its a lovely rainy day today, and the rainwater from part of our roof runs into the pool. Nice fresh water. We did th during the drought when we had water restrictions. But this could cause problems if it rained heavily - diluting the pool chemicals and causing a green change. It also prompted frogs to call and get into the pool so we had dead frogs floating there.

And if the pool should run over then we had salt and other chemicals flowing over our garden and poisoning our soil.

But today with the pool overflowing Charles's little sister can happily sit in the water and the grand old fig tree behind the pool is gtting clean, fresh water into its soil.

But I will have to reduce the level once it stops raining so the skimmer can work.

Saturday, 16 April 2011

Eureka! - the idea forms
In about October last year I was bitten by a snake whilst cleaning out the skimmer box on our pool. The little bugger was hiding under the flap and got me on the finger! So I spent the next 6 hours in hospital being stuck by a multitude of needles to find out whether I had been envenomated. In the end we decided it was a Keelback. Not particularly venemous, and I had not been significantly envenomated.

However my enthusiasm for the pool subsided somewhat and I didn't do any more work on the pool for some months. Hence the pool was without chlorine.

This gave the opportunity to a number of water dragons to frequent the pool, and dragon flies, and water beetles. Watching this from our deck started to be quite a pleasure and the water dragons became quite tame. Emma has named the largest one "Charles" since we are sure that his namesake (Darwin) would have appreciated his beauty.

So now we don't want to add chlorine which would possibly kill but certainy repel our new friends. This caused me to start searching for an alternative management system for the pool. In fact "natural swimming pools" are quite well known in Europe. They use biological filtration in a way similar to that used in an aquarium. This is accomplished by the work of bacteria on gravel filters and on the roots of plants. The result is sweet water that can sustain plants and a complex ecosystem of insects, frogs and even fish!

It is possible to have a pond with all this life as well as clean clear water good enough to swim in!

Our plan is to start adding plants, and as the weather warms up add a tub of gravel and reeds on the edge of the pool. Water will be pumped through the reed bed and fall back into the pool. This will make a water feature/water fall as well as a filtering sytem for the pool water. It is possible to clean the water with plants alone but we would need to cover half of the pool suface with pants and it still might not be enough. The external filter will increase the filtering capacity and allow us to plan and distribute the plants aesthetically.

The water is currenty very clear so we feel there is no urgency to add the filtering system. The weather has already cooled off for autumn so we won"t be swiming for a few months.

The beginning
So we have simply started adding plants!
The step is the obvious place to start. We have some old plastic crates to stand the plants on at the right depth.
Some of them we have bedded into gravel. Last week we visited a hydroponics shop and found some clay beads used to hold plants in that systm. We thought they might work well in our situation, providing bedding for the plants as well as a porous surface area for bacteria to inhabit. But they float! Joe found that heating them in the microwave before plunging them into cold water causes them to sink. Presumaby they absorb the water to some extent. However they are not very heavy and the pots need added stones to keep them securly grounded on the stands in the water.
The stands are quite visible which is not so aesthetialy pleasing.  I think I  will add a covering of shade cloth to reduce their visibility

We have also added floating plants. We have used a floating ring of plastic tubing to hold them together in a raft. We hope the root system might be a haven for insects and fish (when we put them in), as well as giving us plants in a place other than the step. They should also be taking nutrient out of the water and helping to keep it clear. The greenish look of the water in this picture is deceiving. It is actually very clear, but there is a growth of algae on the walls of the pool. In this pictre it makes the water look green but you can see that the blue hose is visible even though it is submerged.


 The look of the pond is very important to me. The pool is very cose to the house as you can see in this picture. We look down onto the pool from our new decks (2 levels). This is both a great advantage and should make for close observation of the developing flora and fauna, and a risk should things not go as planned. 

In the photo you can see how close the pool is to the decks. The pool fence in this shot is temporary. The decks have just been completed and the builders have not yet restored the final fence. For my American friends - pool fences are compulsory in  Austalia. Drowning is the mot common cause of death in infants - we have so many  home pools and dams. So we just have to put up with the fences.

We also do not have our clothes line back yet. - the clothes on the deck are temporary!

Yesterday we went to a gardening expo and spoke with a pond equipment salesman. He told us that this hasn't been done in Brisbane before!!!!!! I do suppose he meant by his company. He said they had done 4 natural swimming ponds in southern states but not in Brisbane. He seemed a bit fearful that the climate might make it too difficult! However he did tell us about his filtration system (biological) which we could install if all else fails, for about $4000. That is great news. Even though this is quite a significant cost, there will be savings made by not adding chemicals to the pool. and not running the pool pump. We will need some electricity for the filtration system but a fraction of the previous power needs. Oh well- we are not new to bucking the system so here we go again!

The wild life is breeding!

This morning when I got into the pool to add a few more plants I found 2 dragon fly nymph skins on the plants. This means that dragon fly nymphs have crawled up the plants to hatch out their dragon flies! We have seen the nymphs on the sides of the pool and have also seen drowned dragon flies. Presumaby they had no way of climbing out to emerge. Now that we have added the plants they can complete their life cycle and emerge succesfully. That gives me a great feeling of success! Also ths morning I saw a dragon fly dipping its tail into the water in our floating plant raft. I suppose this is egg laying. Dragon fly nymphs are voracious hunters and eaters of mosquito larvae, so all of this is very good news.

Please do comment if you want to. I could do with technical comments or just your thoughts about all of this. Do you think we are mad? Mind you this is all reversible. If we change our minds we can take the plants out, add chlorine and kill all of the wild life, reverting to normal operations. But we now have seen the vision of how things could be and would not want to go back. We are determind to make this work.


We live in Brisbane, Queensland, Australia. This is a subtropical climate so naturally we have a swimming pool. In April 2011 we decided to turn it into a natural swimming pond. That means no more chlorine or other chemicals! Instead we will have plants, insects, frogs and fish to swim with!

Well that's the plan. This blog will record what happens - success or failure. I know I am taking a risk making this public but this site will record our progress for our own reflection as well as allowing comment and assistance from our friends. So here goes …