Pond Boss Forums GENERAL QUESTIONS Water chemistry Alum Application to Reduce Phosphorus?

Al:

What is your alkalinity reading of the water? If it's high then you don't have to buffer the alum as much as you do with low alkalinity water - the pH will swing quickly.

Alum should be applied as a slurry, or a liquid, not as a powder. It can be buffered by applying Hydrated lime first to strips in the pond, then go perpendicular to those strips when applying alum. You should have a bottle of pH test strips to check the pH of the water while and after applying it.

The alum works best if applied at a rate that causes P to bind and flocculate to the bottom of the pond, but again, keep an eye on the pH.

Look at the threads in the Muddy Water section, read the first 2 threads and any others that look interesting. That will give you an idea how to apply it.