I have a 2 acre'ish pond fed by both springs and runoff from the surrounding heavy clay soil.

The water is clear but brown tinted.

I took samples and it's acidic (measurement tools aren't great, but) somewhere in the 5-range.

I treated samples with ag lime, dolomitic lime and gypsum.

The gypsum turned the water black, almost opaque.

The 2 types of lime turned is a little milky.

I haven't found a source to try Alum (suggestions please).

From reading here I've learned that the problem is likely dissolved (rather than suspended) clay particles. And, that the continuous runoff over clay soil is an ongoing source of the clay. So, I'm in the process of populating the surrounding area with grass.

Additionally (I don't know exactly where this fits in), the pond is in the middle of a large peat area.

So, anyone know why the gypsum turned the water black? And why the lime turned it milky?

More importantly, how important is it to the health of the pond (sustaining plant and fish and reptile life) to get rid of the brown tint?

And what should I try next to make that happen?

Thank you so very much!