Natural Ponds

I am in the planning stages of my pond, I would like to try and recreate a pond I built in the UK.
the pond that I had was fully stocked with fish, ( 2 koi, 4 goldfish, 1 grass carp and a few others that I can't remember now) I had a small water feature running all the time and the pond was oxygenated mainly by aquatic plants, there was NO mechanical filtration system at all.
within a year our fish had bred and we had around 30 to 40 fish in there.
This pond was running for about 4 years when we left the UK to come to SA and by then the 2 koi had grown to around 300mm long.
I went back to the UK for a short while 3 years later and the pond was still there and still fully stocked ans still all natural (no filters or anything).
I have no idea what oxygenating plants I used but some how I must have got the balance right and created a good environment for the fish.
Does any one know where I can get advice on finding the right sort of plants to try and make this pond happen here?
I will not be getting koi to put in this pond, it will start off just with goldfish. I would however like some kind of algae eater in there maybe a garra pingi pingi if I can find one in this country.
The pond will be lined with a butyl liner and have "shelves" around the sides of different depths to accommodate the plants.
Any Ideas or suggestions will be welcome

 

I have a suggestion - as you are already planning to have a pump in there, why not incorporate it into a filtration system? You could either set it up to run through a massed planting of something like Louisiana iris, or insert the pump in a home made bucket filter (very easy and cheap and effective).

 

A logistic problem I experience with outside ponds is natural enemies..... which include Dragon flies, King Fisher birds, and frogs...... Make sure provision is made to counter their accessability and/or presence...... the rest is easy.....

 

hi eishfish-research wetland pool s.a - will alo advise how the natural filter process can be enabled thru the design

 

Do not forget the dreaded hamerkop either...

 

I will certainly research the planted filter route as I don't want any sort of obvious filter visible. If I can get it to blend in with the surrounding plants I will be happy.
I don't think birds will be a problem with the dogs and cats around, frogs I will happily let use the pond, Makes it more like a natural pond.
I will have a look at wetland pond when I get some spare time.
thanks everyone for the input