We bought our house six years ago. When it was originally built and landscaped (some 11 or 12 years before we bought it) it was apparently a showpiece, but subsequent owners lost control of the garden and it was pretty overgrown in some areas when we got it (there are lots of places that have the potential to be overgrown in an acre and a half).
One of the things that came with the purchase of our house was a set of diagrams, hand-drawn on what appeared to be a paper bag. These diagrams showed how the pond waterfall pump system works, in great detail, and with annotated labels on all the on/off valves. It includes an explanation of how a sand filter is incorporated into this, and instructions for setting valves to flush the system, and so on.
Unfortunately, since we couldn’t find the sand filter, this has not been much use.
Much of my gardening efforts simply go into holding my own against encroaching nature. But every once in a while I whack back some brush and find something interesting. One year I found a smoke bush and then a couple of years later I discovered a current bush. And then yesterday I beat my way into the depths of some dense salal and hardhack to cut down a small tree that had died, and found… this.
It’s the top of the sand filter! Hurrah!