I filled the pond from a tank of collected rain water. Don't use water from a tap or hose, especially if you are installing fish because the chlorine will kill wildlife. I used a standard PVC pond liner and it has managed to hold water for 8 months without any leaks, just make sure that the earth is free from sharp stones, sticks etc before installing. It's also a good idea to put a pre-liner in to act as a barrier between the lining and the earth. When the weather is hot it may need the occasional top-up due to evaporation... waterfall features tend to make the pond evaporate faster.

If you do this project make sure that the entire perimeter is completely level. I thought I did a good job until I added water and noticed there were a few low spots which ruin the look of the pond. Also make sure you buy a liner that is too large... that way you can easily modify the perimeter so the the liner is completely hidden before removing the excess.

It's definitely a rewarding project to do, I hope you have success building yours :).

Tom Pownall thanks a lot but i cannot put fish. winter is kinda bad. they will freeze..

I have a filter installed which keeps the water nice and fresh. You can get ones with UV light which takes care of the green/brown colour. I have fish in my pond now and since they've been there the mosquitos and midges have dissapered.