It's a pretty good clarifier.

Back in the day when Buckman still held a patent on it, they sold it as a microbiocide under the label WSCP, and as clarifier under a different label for 50% less. It was during that period that requirements for MSDS info was first being enforced widely, and when I got my hands on the sheets for the two products, I recognized the labeling difference. Since I was not selling the product, but using in directly in large commercial pools, I purchased a couple of 55 gallon drums of the 'clarifier' for use as, well, an 'anti-algae clarifer'!

Buckman caught on to this practice fairly quickly. Apparently some resellers were packaging polyquat, but buying half of the stock as WSCP and half as the clarifier. Buckman did NOT approve!