Originally Posted By: halfastro
bobad,

Is there a difference in long term ability of different coagulants to help keep a turbid pond clear? I am under the possibly false impression that gypsum lays on the bottom and helps control the suspended clay going forward. I'm not saying excess gypsum laying on the bottom will keep the pond clear, just that it adds some concentration of positively charged particles to the mix and will help you control the suspended clay with less addition required going forward than the original application. Perhaps it's just wishful thinking.

Not sure if alum works similarly or not although I suspect it does, I was too afraid of the pH swings to try alum.


Sorry I missed your post.

I don't think it matters which chemical is used as long as you use sufficient quantities. (And watch your pH)

Spreading an insufficient amount of chemicals can clear up water instantly but temporary. When a sufficient amount of chemicals are dissolved in the water, it will permanently clear it up. Permanently that is, until you get a lot of rain and lose your expensive treated water over the dam.

Alum is the easiest to dissolve of the common remedies. You can pour a pile of it in a corner of the pond, and it can be detected in the far corner 1000 feet away within an hour or 2. Gypsum dissolves more slowly, and needs spreading.

I've seen ponds that have such a high chemical load that you can stir up mud on the bottom, and watch it settle perfectly clear before your eyes. Water like that is usually the result of evaporation during a long dry spell, which concentrates the chemical load.

Shrimp