We do get an occasional visit from a heron - even though we have no
fish (I assume it likes tadpoles and frogs just as much). Along with
the problems of excrement, this was the main reason for avoiding the
fish - but this may be worth a go.

I have been amazed at the amount of wildlife that has found its way to
the pond in such a short period of time. Masses of dragon & damsel fly
nymphs, newts, water boatmen and various aquatic snails. How did they
all get there so quick?!

I have in the back of my mind someone telling me that snails with
pointy shells are bad for the pond, and flat ones are good. Is there
any truth in this? Some of the pointy ones in my pond are over 2 inches
in length!

Thanks for the advice

Michael.