Catherine - Take some of the underwater pond plant to the local soil and water conservation office. They may be able to identify it for you. If not try to get a "good" close up digital picture of it and email the picture to me and I will try to identify your unknown "weed". Sometimes a picture of it in a mayonase jar full of water is helpful to see the leaf and stem structure.

What are sun perch? Do you have another common name for them?

With only bgill and sun perch in the pond you will soon be overpopulated with these two types of fish. When over populated, bgill will frequently nip at the swimmers which can be very annoying. Bgill are nipping at body parts (hairs, moles, nipples) that resemble their normal food items. Larger bgill when biting trender moles or nipples have been known to draw small amounts of blood. These bitting fish scare you more than hurt you. One or two hybrid stripped bass that you plan to stock will not control the offspring. In a few years you will have a very out of balance pond that is overrun by stunted fish.

aka Pond Doctor & Dr. Perca Read Pond Boss Magazine -
America's Journal of Pond Management