Ah, the Pond. Looks like a wonderful opportunity to make a wasteful swimming pool into a productive garden. Just a bit concerned about the Salvinia - it's a declared noxious weed. It would be suitable to be composted. Duck weed (lemna sp) is quite tiny and sits flat on the water - it's possibly the world's smallest flowering plant - and azolla is a water fern but still a lot smaller than Salvinia. There's a 'water lettuce' which grows well in Brisbane but is also a noxious weed and should be composted or dumped in the rubbish if you find it in your pond. Pity, though ... both are good plants in their own ways and the frogs love them *but* they are enthusiastic growers and really do choke up our waterways.
the pond is amazing - from energy consuming swimming pool to abundant food source - wow. I'm installing a pond in our backyard (nothing like this scale though!). I'm planning to grow taro (half submerged pots) and water chestnuts in it.