I see...

duck food,
ducks,
and a small amount of water.

These things add up to a nutrient laden ecosystem. The ducks and the food have to go hand in hand and the fountain size it not going to be increased, obviously, but getting rid of the ducks will help your water clarity. Keeping the ducks will likely aid the health of any plant life in the pool, which is lovely by the way, but the water will be greenish.


Fish on!,
Noel