Waterline Microbial Contaminant Control Tablet (1 Liter & 2 Liter Tablets)Citrisil is the only all in one shock and daily maintenance dental waterline tablet. Use the orange shock tablet in your lines monthly; allowing it to work overnight to kill pre existing odor causing bacteria. Use the white or blue maintenance tablet in your bottle daily to continuously clean and maintain dental waterlines. Drop in a new maintenance tablet every time a bottle is refilled. The tablet effervesces and continually stays in the lines to