A flocculant or in other words a coagulant is a chemical substance capable of clumping small suspended particles which are most frequently algae residue, organic matter, etc. Their occurrence leads to milky turbidity of the pool water. A traditional sand filter is not capable of dealing with the condition alone as the super finely distributed particles cannot be caught by the filter medium. Flocculation (using e.g. Superflock or SuperflockQuickflock Super) makes the fine particles large enough to be held back in the filter.

Both liquid and solid flocculants are available, the latter ones used for continuous flocculation, the former - when a quick action is necessary.