I just added one of those porcupiny structures to each small pond.

https://www.amazon.com/gp/product/B001BAAVMK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

They have 26 holes for 1/2in PVC. We guestimated the water depth and put 18in pieces in the holes. Sorry no pic, I just have a flip phone. We'll see what the denizens of the deep have to say.