Yes anti sync is basically one pump doing the opposite to the other, as one pump ramps up the other will ramp down. This can be setup on the child pump, and for some reason the setting is called phase (set to 160)
The only time I can hear my pumps are if they are running at around 80% and I have my head in the cabinet lol, even then it's a faint humming.
Standing next to the tank I can't hear anything.
So my second pump. If I put it full on child and phase 165 it will do exactly what the other one will do? What is the difference from the phase %'s?