Hello,

I have a pond (125' x 300') that has brown water. Lots of organic material around, peat, and clay.

I tried a little experience with a couple of samples of the water. I applied Ag lime to one and gypsum to another.

I was hoping someone could help me interpret the results? I thought I had a picture of the samples before treating but I might have forgotten. The water clearly had plenty of suspended and/or dissolved clay in it. But now, couple of weeks after treating, one sample is clear but very brown tinted (gypsum) and the other (lime) is mostly clear and untinted.

Does this tell us anything useful?

Thank you!

[img]https://ibb.co/s6HGDV3[/img]

I would want to know the PH range.

I use both, gypsum as a flocking agent and ag lime for low PH. If it's a clay pond, it probably needs lime.

The pelletized gypsum has a brown tint to it.

Yes, it was the pelletized gypsum that I used for the test. Do you think that is the cause of the current brown water (despite the water being brown to begin with)?

PH was pretty low -- mid 5's best I can tell with my pool testing chemicals.

And the ground is 2-3' of peat, underneath is clay for quite a bit, then a mix of gravel/clay/sand. It's one big watertight soup bowl.

Would love to hear expert's suggestions on how to clear it.

Thanks!

Use lime because the pH is low. Peat bogs are very acid and will influence your water. To somewhat neutralize the acidity use lime. If you do not get the result needed - clearer and pH neutral (7) then mix lime with gypsum.

https://srac.tamu.edu/fact-sheets/serve/108

The brownish color could also be caused by the tannin in the peat staining the water.

Alum can also clear the water but you have to buffer it with Hydrated lime or the pH could drop low enough to kill the fish.