I rely on 3 main,water plants to achieve soil fertility and to help build organic matter in the soil,we have other spiecies in the pool that operate as support spiecies and also food plants.All plants help balance the nutrient load and polish the water.They provide habitat for micro and macro flora and fauna.The first of my useful water plants is Azzola pinnata the plant is host to a cyno bacterium called Anabaena azollea.Cynobacterium are an important part of the earth oxygen production some place it's importance at upwards of 60% of oxygen production.They exist mainly in oceanic geyers that are located in several different water bodies throughout the word.Anabaena is also a symbiant that has the ability to fix nitrogen from the atmosphere to help this small fern grow in nitrogen scarce enviroments.It is this function I am chasing as nitrogen plays an important role in leaf production in my home garden.I have read that Azolla filiculoides is better at this function and increases it's usefulness if put through a simple ferment process.The second important plant we utilize is Eichhornia crassipes or water hyacynth,this plant is able to reproduce itself at an astonishing rate in scientific trial up to 90 tonnes wet per year per hectare.I have found that my pool which is 8 meters by 4 meters and about 70000 litres,could be covered three times between spring and Autumn,in winter the Azzola becomes more dominant.We find that this is more than enough mulch for the garden when combined with other support spiecies cajunus cajun,crotolaria, cana edulis,symphytum officinal,which are all planted extensively.The hyacynth also rapidly accumulates phosporus and potassium two things that are associated with algae out breaks.Algae can smother the pool and deplete oxygen and the stunt the ability of the other food systems (zooplankton and phyto plankton) from functioning properly.

Wolffia sp or duckweed is our third spiecies,it is the worlds smallest flower,it is about 40% protien and can be used as food,we find it a good addition to our chickens diet and in a pinch I believe that I would eat it too.We are at the moment harvesting approximately 100 grams of small native fish per week to suppliment the protien requirements of the chickens as well.These fish have the role of mosquito control as well,however other spiecies such as dragonfly nymphs are voracious predators of mosquitos.in general mosquitos have not been any issue.We include reeds as perches for dragon and damselflys as they are excellent benificial predators enjoying aphids and other common garden pests.We have quite a number of spiecies of both.The also need the reeds to emerge from the pond and then transform into dragonflies from the nymph stage.A 1000 litre water tank connected to our downpipes keeps the pool topped up a small hose runs from the tank to the pool in rain events.We have a 5000 litre water tank that can be used in times of extreme dry.I have included pictures of the hyacynth on the garden before it is processed by the lawn mower,this area of 8x 3 meters takes about 15 minutes to mulch and mow so it is drop and chop not chop and drop.The after pictures reveal a spongy mass of dark material roots and leaves that are then covered with the other support spiecies.The pool has been a facinating journey for me and it is very rich in learning and observation,I will continue to update on certain other elements as time allows.I would like to thank Fernando Pessoa for giving us the initial help and advice on this endevour as it stands we are more than pleased with our choice.Earlier pictures of this system are available at the PRI website when Craig Macintosh was kind enough to visit us and do a story you can read it here.

http://permaculture.org.au/2009/07/21/convert-your-eco-unfriendly-swimming-pool-into-a-biologically-active-and-attractive-fish-farm/