I think I misread your post, you appear to be talking about sleep mode, not power-down... I believe the PSU stays ON during sleep mode, so the aquaero stays on.
This thread is dated, but suggests using hibernation instead of sleep mode.
Best Answer: Instead of putting the computer into sleep mode, enable hibernation on your machine and put the machine into hibernation instead.
Check the advanced settings in Control Panel for Power Settings, click the "Hibernation" tab and enable hibernation.
It will create the necessary hibernation file on your hard drive that will be approximately the size of the amount of memory that you have on your computer.
The next time you want to put your computer into standby, select "Hibernation" instead.
It will take a bit longer to start up, but you won't be wasting any power.
Edit: Alternatively
AMP WinOFF may be useful to you.