You can do both. You can keep the yard under control and still have butterflies, bees, birds, etc. I don’t fertilize, bug spray, etc and not only is my yard a bitch and a half to mow if I let it go or can’t get to it, the wildlife that is making the yard home is awesome.
I have a huge yard and do my best to keep it under control, I still have a ton of birds, butterflies, fireflies, etc in my yard all the time. I even saw a groundhog or similar the other day.
You definitely need the pump, the best thing about koi or gold fish is that they grow to the size of the environment. You also need to make sure that you have enough algae helping to oxygenate the water (for others reading, not necessarily you in particular).
It can take some work to get things just right but once it starts maintaining itself (for the most part) it becomes it’s own little world.
Some closing advice for those who live in the part of the world where it gets and stays at or below freezing for weeks or months on end, don’t mess with it when it freezes over. Turn off the pump and leave it alone, the fish will hibernate and will wake up when it’s warmer. This means keeping kids away from it that may want to poke at the ice.
Just add fish. Koi do extremely well in small ponds, I have built and maintained a few of them over the years.
I love seeing stuff like this. Iirc, panels are given a 25 year lifespan. If most panels will last this long and longer, it would only make sense to replace/upgrade when they actually break or there is a significant enough increase in efficiency to make it worth the investment. Not unlike the batteries in evs lasting longer than even the original engineers estimated.