Murky mucky mud

We hadn't cleaned the pond in 3+ years, since before Mabel. Yesterday it was time. It was actually way past time, but so it goes with little ones--time speeds up and to-do lists quadruple.

Last summer the fish population peaked at 15, now we're back down to 2. Predators get them and a few times I've found a dead one floating. The floaters get buried with a little ceremony akin to Garden State.

A couple hours of later, the plants around the pond are mulched with nitrogen rich muck and the pond was refilled with rain barrel water. We've tried barley powder to keep the algae down, but I'm not great at remembering to add it weekly.  I know we need more shade to keep the bloom down, but I'm also thinking of trying bokashi ceramics like these folks did. Do you have a pond? How do you keep it biologically balanced?