Have you reviewed the minimum power settings for the fans. For example: if you set it to 20% you will never come any lower in the regular fan control since the aquaero will map the minimum and maximum setting into the 0 - 100% range.
So if you would set 50% as minimum and 60% as maximum, a setting of 80% in the regular control would result into a real value of 58%.
This setting seems to have an effect (Beta11) on the fan revolutions at 20%+, but setting it to zero does not turn the fan off.
Sorry about the late reply.