Hardy lilies can overwinter in the pond in cold climates. Bog plants can be moved to deeper water for the winter to ensure their survival. Introduce fish after the plants have started to grow. Feed fish once a day, and only as much as they will consume in 5 minutes. Fish will cease feeding when the water turns cold.
Fish can survive for weeks without supplemental food provided that the pond is teeming with life.
Pet stores sell food specifically for pond fish. Do not become alarmed if algal growth appears to be excessive shortly after filling the pond. This will subside when the water lilies begin to shade the surface. It is best to wait until this initial algal bloom is over before introducing fish. Do not drain the pond and refill it, or the algal bloom will happen again.