Abstract WHERE AT LEAST ONE OF THE R''s, which may or may not be the same, is a substituted group, for example alkyl, aryl, cycloalkyl, alkaryl, aralkyl, etc. and derivatives thereof. An example of a compound which is not itself a guanidine type compound but is capable of forming a guanidine-type compound is cyanamide NH2CN which reacts with itself to form dicyandiamide. RESIDUE AND MAY BE ILLUSTRATED BY THE FOLLOWING: The use as a water clarifier of the compounds formed by reacting guanidine-type compounds with polyamines. The compounds are formed by the reaction of guanidine-type compounds, (including compounds which although not guanidine-type compounds are capable of forming guanidine-type compounds). In general, guanidine-type compounds are those which contain the