Most AiOs ship and function with their pump speed set to max/100% out of the box while under load. While I have a CLC280, I don't have it installed yet, so I can't confirm it works the same way as all the rest. But since it uses the same Asetek pump as so many other brands, it's a probability. Per Gamers Nexus, my personal choice for hardware recommendations, they normally set AiO pump speeds to 90%. It's fast enough that it does not result in any higher temperatures compared to 100% while under load, but is slow enough to prevent noticeable pump noise during use.

So whatever options you have in the Flow Control software, try to set a 90% pump speed for a 60c CPU die/package temperature. Not the AiO liquid temperature, but use the temperature sensor for the CPU itself. CPUs can certainly run hotter and be safe, but 60c is typically the target you want to shoot for under a gaming load. That leaves a small amount of headroom for your curve to increase to 100% for the pump, along with your fan curve, if you start going over 75c.

Whatever you want to set below that for temp/speed is really up to you. You may need to play with it a bit to find the performance you want. Pump speed isn't like fan speed where you can set it to a very low speed/%, even when idle. You have to keep that fluid moving through the system, even if the fans aren't spinning very fast because the system isn't under load.

My ASUS X99 motherboard adjusts speed when temp rises.

After quite a bit of playing around with fan speeds and pump speeds on the EVGA 240x120 CLC I can say anything above 1200RPM on the fans made it unbearable to be in the same room as the PC. I also found they did not make a lot of difference to the temps. So i adjusted the aggressive fan curve,
25% till 45 degrees then it bumps to 50% fan speed at 50 degrees to 100% at 60 degrees on an i5 7500k and pump speed to full also adjusted the fan curve in the bios a little as well as it was set for stock cooling.
 
Idle temps are about 25-30 degrees depending on the weather and after a long gaming session the fans tend to annoy me but not as much as they did before. I cant even hear the pump and just hear the fans at 900RPM while below 50 degrees. I hope this helps anybody out. Also if your fan speed is not showing in the Flow Control software change the bios setting for CPU fans to PWM and you should be good to go.