(1) To fill your water flosser, flip open the cap on the back of the water tank and fill with clean, lukewarm water (under 40degrees). You could also add a few drops of Ordo Mouthwash Concentrate for extra freshness. If you use mouthwash, run a full tank of fresh water through the flosser after use, to avoid residue build-up.(2) Short press the mode selection button to scroll through the 3 pressure settings:1 - Sensitive Mode (low) – recommended for new users.2 - Daily Clean Mode (medium)3 - Power Clean Mode (high)You can change modes whilst using your water flosser.(3) Lean over the sink, place the floss tip in your mouth and part your lips slightly to allow water to flow out. Press the power button to begin flossing. Alternatively, press the on-demand button to control the flow of water – press and hold for a continuous flow and release to stop.(4) Hold the floss tip at a 90degree angle to your gum line and pause in between each tooth to ensure a thorough clean. Clean along the gum line as well as between teeth. Clean inside as well as outside surfaces. To get the most from the water tank, do not tilt the water flosser back during use.To help protect your water flosser, it will automatically turn off after running for 2 minutes.(5) Your water flosser has a 260ml tank capacity, which provides 55 seconds of use. We recommend 2 full tanks per flossing session, one for the top teeth and one for the bottom. Make sure the tank is fully emptied after use and open the cap to let it air dry. Wipe down the floss tip and main body.(6) To deactivate your water flosser for travel or storage, press and hold the mode selection button until the red light begins to flash, at which point the Lock Mode is activated. In Lock Mode the lock light will flash 5 times when you short press any button. Simply press and hold the mode selection button again to unlock the device – the last used mode will illuminate once your flosser is unlocked.