I agree with Greg about it being pithophora-type. Taking care of a pond requires a tool box. A carpenter will have a tool box that includes hammers, screwdirvers, saws etc. He will not use a saw to pound in a nail but he still has that saw in his tool box for use when he needs it.
That being said, a pond will require tools like chemicals, dyes, aeration, plants, fish and off-water management like keeping the lawn fertilizer at least 10 feet from the pond's edge. Getting the right mix of all of these tools and using them how they are designed to work by mother nature will allow you the perfect pond you desire.
If I had that pond, I would start with a tretment of copper and diquat to treat the algae (if that is what the problem weed is), followed by a small planting of native plants like arrowhead, pickerlweed, bullrush, iris, placed in monocultures to allow windows of access to fish. I would add aeration based on a design by one of the advertisers on this site, followed by a fish stocking again designed by one of the consultants who advertise on this site. Lastly, I would do my best to reduce the nutrient loading created on land, i.e. fertilizer, wash in from the driveway and off the roof of the house. Keep us updated on how you proceed.
