Garden Ponds, Water Basins

[Pasanna]

Just cleared out a water basin in the garden, it was full of ash saplings. It's water tight and approximately 170 cm in diameter and 80 cm deep. Does anyone have any advice for ( preferably) solar powered pumps/ fountains to use? We live in France so sunlight isn't a problem and I need to keep the water moving to stop it becoming a mosquito breeding ground plus a friend has promised us some baby koi carp.
I would like to put in water lilies but have no idea what else to plant. Any suggestions gratefully received!
I'll go and take a photo of it now.

[Pasanna]

Here's the pond