[jtriangle]

You likely have a setting for fan ramp time in your bios, usually in seconds. So setting your pump to always run at 100% and your fans to ramp slowly, say 10 seconds or longer, and using a minimum fan speed that is as high as tolerable would likely work as a no-additional-code solution.

[jeffbee]

An AIO pump running flat out will draw 25W all by itself. An idle CPU can be below 100mW (Intel ... AMD idle powers are slightly higher).

Setting your AIO pump to static full power will greatly increase the idle power consumption of the machine.

[jtriangle]

And?