Water is coagulated by adding alum, which makes the lighter impurities heavy and helps them settle down. Water coagulation is done to purify water.
"nag a ram" OR "ram a nag" OR"mar a nag"
A 7 letter anagram? No, it doesn't.
to rearrange (the letters of a text) in order to discover a hidden message
Thaw is a possible answer.