1Bottle Toilet Tank Cleaner: Automatically cleans the entire toilet flushing system, with a long lasting fragrance. After using the blue toilet tablet, a thick lubricating protective layer forms on the sidewalls, effectively preventing dirt buildup while keeping the toilet clean and fresh. 2Long Lasting Cleaning Power: Designed with slow release technology, each toilet tablet bottle can last for 30 to 40 days at room temperature (25). The odor removal ingredients help maintain a fresh and clean scent in your toilet. 3Reliable and Safe: The toilet tank cleaner is professional and safe for use in your toilet system, ensuring a clean and fresh smelling bathroom. It is recommended to flush the toilet before using this cleaner. 4Instructions for Use: Remove the outer plastic film, but do not open the lid. Place the bottle at the bottom of the water tank by hand, keeping it upright. Ensure that water flows into the cleaning bottle through the four semi circular openings, fill the bottle with water, and avoid it floating on the water in the tank. Wait for at least 10 minutes for full dissolution, then flush after the water turns blue. 5When to Replace: When the toilet cleaner completely dissolves, wear gloves to remove the blue bottle and replace it with a new toilet cleaner. This toilet cleaner is safe and will not damage any metal or plastic components in the septic tank system.