EZ Clor Drop Out is from a family of pool chemicals called flocculants. No matter how well your pool filter functions it does not filter out everything. There are many small particles that are not caught by your filter and continually circulate throughout your pool untouched. This is a common cause of “cloudy water” and also can potentially become a sanitation issue. Enter Flocculants. Flocculants work by taking these small particles and clumping them together into larger particles that can be caught by your pool filter. This leaves you with not only cleaner but clearer water.