ClearWater 1 Litre Clarifier is an extremely effective way to prevent pool water looking dull and cloudy due to dead algae, skin cells and other dirt and grime that's too small to be trapped by a filter system. The swimming pool clarifier contains flocculants, chemicals that bind small particles of dirt together so that an above ground pool's filter system can successfully trap them. These tiny particles of dirt can make pool water look cloudy and uninviting. Over time they can also transform a pool into an unhygienic environment. If your above ground pool has been treated for algae using Clearwater Algaecide you'll need to use the water clarifier to clear away left-over residue. Application simply involves backwashing the filter, returning it to its normal setting and pouring the recommended blend of water and clarifier into an above ground pool. As with all chemical products instructions should be carefully followed and precautions taken, thankfully ClearWater 1 Litre Clarifier is clearly labelled with all of the necessary guidelines and warnings.