Some random thoughts ~

Smaller is always harder to balance than
larger.

You are right to clean it out every year.

Shade and temperature. May be too shaded for
lilies and too cold for the toad eggs to hatch.

The snails and mussels may not have enough
food to survive, also mussels like moving water.

kathy :-)
help move the band out of the basement
http://www.battleofthebands.com/batt...nds/theloshas/