Awesome job, looks great. Your pumping way more than 750 GPH (which is good) Looks more like 1500
I can see your not into fish but if you ever decide you can go a a store and pick up 10 "feeder goldfish" for less than $10, throw them in there and let them fend for themselves, survivors will get quite big over the years and will survive under the winter ice too. They will add fertilizer for the plants too and you dont have to feed them but couldnt hurt for some food pellets every few days until the pond is more established.
If not, glad you are enjoying the sound of rushing water!