My backyard pond turned green enough that I could barely see the fish. Here is the exact pump, 36W UV clarifier, DIY 5-gallon filter, 20-PPI foam, lava rock, bypass plumbing, mistakes, and before/after results from my real 1,200-gallon pond.
I built a simple 5-gallon bucket pond filter using 20-PPI foam and lava rock for my 1,200-gallon pond. Here is what worked, what I would change, and how I would build it again.