Originally posted by KenB:
If you collect the water in a glass, it is relatively clear with participates floating around, but I wouldn't call it muddy.
It's just stain from the oak leaves. If the PH is normal (apparently so, as there is a good diversity of fish and critters), there is no problem with low PH or low DO. Shade around the pond can exaggerate the appearance of the stain. If it was in full sun, it would look a lot more clear. The stain would still be visible, just lighter.
Maybe cut some overhanging limbs and/or plant some flowers or shrubs to act as leaf barriers.
