Fluval “Quick Clear” Water Clarifier (4 oz) rapidly clears cloudy or hazy aquarium water by clumping fine particles so they can be filtered out. This flocculant works on microscopic debris, such as stirred-up sediments or algae bloom cloudiness, restoring water clarity often within a few hours. Quick Clear is safe for fish and plants when used as directed and is ideal for polishing aquarium water after maintenance or whenever clarity is not at its best.