Tom Puskar wrote:

My question is if I establish a lily pond do I need filtration? I
wouldn't put fish in it but am concerned about stagnant water.

Any advice would be appreciated.

If it's well planted - put in submerged plants as well as lilies - it'll be
fine, but you might want to put a couple of fish in there just to ensure
you don't have mosquitos. Dragonflies and frogs will likely solve that
problem, though.
--
derek