B3 is the highest note in the third octave. If you like this tone for your lowest note in your set of crystal singing bowls, you might consider adding E4 for grounding tones (Perfect 4th), F#4 for total relaxation (Perfect 5th) or G#4 for expanding tones (Major 6th).
Not sure what note is the lowest in the third octave?
This is the order of the crystal singing bowls, lowest to highest in the third octave. C3, C#3, D3, D#3, E3, F3, F#3, G3, G#3, A3, A#3, B3