"BoyPete" wrote in message
...

Hi, pardon my ignorance, but can you explain what 'flocculate' is?
TIA

http://dictionary.reference.com/search?q=flocculate

Turbid water is formed by suspended solids. Basically stuff floating around
in the water clouds it up. To improve water clarity, you need the solids to
settle. Alum and other flocculating agents clump to suspended particles and
make them heavier so they settle to the bottom of the pond faster.

-S