I measure the amps on the 50 amp breaker the black wire measures 23.5 and the red wire measures 23.2 do I add these together or is the spa pulling 23.5 amps?

If there was a white, it would measure 0.3 A, but I'll bet there isn't and your within the error bars of the measuring system.

Call it 23.5 A and use the error bars of the instrument.