Turn the "T" on your Watts Premier's adapt-a-valve clockwise until it stops moving; this turns off the water supply.
Open the RO faucet to drain the storage tank into an old container. Close it once you are done.
Disconnect the blue tube from the storage tank's ball valve by by hand. To do this, push in on the tube's collet and slip it out.
Use an eyedropper to add a half teaspoon of hydrogen peroxide or bleach to the blue tube.
Attach the blue tube back to the ball valve by hand. Turn the "T" on the adapt-a-valve to turn the water supply back on.