I have mine in my bog, but they will do well in your pond also.
from the net:
Plant the Pickerel Rush in a 5-gallon or larger pot to accommodate strong and plump roots. The pot should be placed in sun to part shade, and the plant will bloom in late spring through early autumn. Divide plants in spring while pruning away the rotting portions from the previous year. Stolon cuttings may be taken in summer and started, or a new plant may be started from fresh seeds collected in late summer and planted. Zones 4-11.
Place the plant in 2 to 3 clusters in a large pot, covering the roots with 2-12 inches of water, because the plant can grow to a height of 4 feet.
The Pickerel rush requires full sun to grow and bloom between May and October in order to flower. The plant itself can grow to 4 feet and does an excellent job of filtering your pond water. The roots systems filter out algae in great quantities, making this plant invaluable in the pond.