Start at the lowest setting and work your way up as the water stream is powerful. It is worth it to note that each of the tips produces a different pressure stream so that one level of pressure does not work for all the tips. For instance, using the toothbrush tip produces much less pressure on the No.3 or 4 setting than it does for one of the other gum or braces type of tip. You'll have to make an adjustment. Also, the motor is VERY loud and rough-sounding to the point that each time the unit is turned on, I think it might be the last...
Recommended by my dentist, overall, this Waterpik was worth purchasing.
Verified purchase: Yes | Condition: Pre-owned