in-Swale Chemistry Experiment

I decided the throw some calcium sulfate in the muddy swale water to see what would happen.

It completely cleared the water of it's muddiness and now is crystal clear.

Could someone help me to understand what went on, chemically speaking. I barely passed high school chem 1.

I added some pics just to drive the point home of how clear it made the water.

Thanks,
William

You've discovered flocculation.

The simple explanation? Calcium is a +2 ion, so it has two arms reaching out, able to grab some negative charge. It can pull things together like a parent reining in toddler twins headed in different directions. Sodium can't do this. It is only a +1 ion, so if it grabs onto something, it just goes along for the ride wherever the negative charge was headed.

So the calcium is binding (with what?) in the muddy slurry to form a floc and then sediment itself to the bottom...?
Thanks.
William

Clay particles that are so light that it takes them a very long time to settle out. But once a few particles get agglomerated together, courtesy of the calcium ions, they are big enough to settle.