Posted: 08/08/2014 at 15:32
I have had the same pond for over 20 years and it has never had a filter or fountain.
Several goldfish which breed every year and a couple of tench.Plenty of frogspawn in the spring,toads and newts as well.
I used to have a problem with blanketweed but use 'Blanket Answer' now and all is fine.Green water I treat with barley straw extract to some effect.
It is not a huge pond and I clean it out completely once a year (usually in spring) and re-pot plants and remove sludge at the bottom etc.
I also have a tiny wildlife pond which gets the same treatment but does not have any fish in it.