do not use simplegreen, it is not green except the green dye.
Use bleach. Bleach is what your municipal water supply has in it (a form of bleach anyway). Unscented bleach is safe to disinfect your drinking water tank as long as you rinse it out after. It does not take much. One gloop will do. fill water tank full with bleach (1/4 cup or 1/2 cup of bleach and make sure it gets washed down the tube to the tank, do not add it last). drive around to slosh it around, or just let it sit overnight. Drain tank, add some water, drain, run some water through... Most of the bleach will evaporate in a day anyway. Be sure to run that bleached water through all your spigots and shower heads and toilet for a full clean. When it does not smell like bleach then all is good.
