The ecological water stream in the garden uses the bog filtration method: that is, a coarse gravel bedding is poured into the stream to filter the water, aquatic plants are planted on both sides of the stream to absorb the nutrients in the water (the plants also purify the water) and then the water is pumped to the very top of the stream and then flows naturally downstream. This way there is no need to replace the water and maintenance is largely unnecessary on a daily basis, just a little electricity and soon the little ecology is up and running.