On my XT they ramp up the fans to 100% when they reach 95°c, That was using the standard fitted heatsink that came with my XT well over 12 months ago), But with a water block they never get close to this ..
AFAIR when amps hit 95 C then the electronics forces them not to adjust the voltage, so they will cool down.
After dropping below 70 C they start to control voltage/current again, so they start to heat up.
So in the worst case scenario you hit 95C and then fans start to spin with full speed, because aquaero tries to not to burn the amps.