About the only thing I might add if plants aren't enough--and they should be, based on your pictures--is maybe some air stones. I find they get the plants to grow more vigorously, and the fish like them if for some reason conditions get bad.
I've only had my pond for six years, and it is in pretty much its sixth different iteration. Every year, some older plants die off or reestablish in odd places and thereby create a whole new baseline, making the pond look "natural" in an entirely new way. Every year, I think I have things just the way I want them, but then I discover that the pond has its own thoughts and wants to be what it wants to be. I always end up agreeing with its wisdom. Ponds evolve, and I really enjoy evolving with mine. A pond is a vibrant ecosystem, and if it is big enough, and if you just monitor to make sure there are no major disasters, the pond will regulate itself over time.
The main thing creating algae in my pond, I think, is birds. They LOVE my pond, stream, and waterfalls, and they "share themselves" as the bathe in it and drink from it. And so I allow fast-growing plants (basically, water weeds) to take advantage of the birds' nutrients, thinning them out when they get out of hand. Another nice thing about plants is they drop seeds and such that might not emerge for a couple of years. I have plants growing in my pond this season that I hadn't seen in my pond in three years.
Ponds are fun but work. Just roll with it, and trust that a light touch will usually be enough. I only lose fish from herons (arrgghh) and when fry swim into the skimmer (rarely). This is not something I could say the first two years I had my pond. Trust yourself, but even more, trust your pond.
