Benign Vanilla wrote:
Sunday we had no rain so went back to the pond to play. I was
disgusted by the still orange water, so I decided to clean it. I
decide to empty some water, and ended up doing about a 75% change. In
the mean time, I scooped out 5 inches of clay from the bottom of the
pond...

Might just work...

At work we use a polyelectrolyte solution to rapidly precipitate fine solids
out of suspension. It works just like the "green water" treatment chemical,
gathering the fine particles into bigger lumps that can be easily filtered
out or pumped off from the bottom.

So have a go with "GreenAway" or similar on your clay suspension.