Just a reminder to be extremely careful about which plants you put into your pond -- an image search for "water hyacinth invasive" or "Brazilian elodea" will show how easily waterbodies can become choked by plants with no natural native controls. Even if your pond has no outlet to streams or other ponds, visiting waterfowl or mammals can carry fragments away to other sites, and a fragment often is all it takes to begin a new infestation. Municipalities and lake associations are spending millions of dollars on battles (often losing battles) to eradicate non-native growth that can completely overwhelm an ecosystem in a frighteningly short time. If you're lucky enough to have a native-plant nursery in your area, and even luckier to have one that carries water plants, they'll help you select amphibian-friendly species that'll be more well-behaved if they escape into the wild.
Sorry for the lecture; our small lake is struggling with a couple of invasives here, and other lakes nearby have it much worse, so we try to help other people avoid the nightmare whenever and however we can.
