Dual Action Sanitizer and Shock - Clorox Pool&Spa All-in-One XtraBlue Chlorinating Granules can be used to sanitize and shock your pool water clean and clear. Cleans and clears water in one step. Quick-Dissolving, Fast-Acting: These quick-dissolving, fast-acting chlorine granules not only kill bacteria but are also stabilized to protect against loss from sunlight, ensuring your sanitizer residual lasts longer in your pool water. For Clean, Algae-Free Water. Kill bacteria and stop green, mustard and black pool algae with All-in-One XtraBlue Chlorinating Granules. The multi-functional XtraBlue formula kills and prevents all types of pool algae, kills bacteria, and reduces eye irritation and chlorine odor. Improves Filter Performance: This product destroys contaminants to aid filtration, helping to clear dull water and enhance overall pool clarity. Enjoy a cleaner, more efficient pool filtration system. Clorox Pool App: Test like an expert anytime, anywhere with the Clorox Pool App. Solve common swimming pool problems and get personalized product and dosage recommendations