Waterfall/pond design -help please!!!
I have a very small pond (75 litres) at the base of a slope adjacent to a wall. I have extended the garden up the slope and am removing the brick wall next to the pond. As such I would like to install a 'waterfall/stream' feature on the slope running into the pond from above. I've no idea where to start once I've removed the wall. I have lots of large and small decorative stones and gravel And will take advantage of existing slope. My questions are
1) if the existing pond is 75 litres how large does the upper basin need to be?
2) what size pump will I need?
3) do I just need to use a pond liner and sand under the stream/waterfall section?
4) any step by step plans available as don't know where to start
Any other advice welcome please.
PS Single mum on a budget doing all the labour myself.