Hi. Have been running fedora for some months now. But have still not adjusted my fans. I have liqued cooled pc and i have a corsair commander pro with two temperature probes. They are located at intake and exhaust, so what I did before in windows was controlling the fan speeds based on the delta of these two. Cant seem to find any fan control software that allows me to do this. Is it hard to calculate the delta of these two and make it appear as any other sensor? I found the input files in /sys/class/hwmon/hwmon0 (temp2_input and temp3_input).

Have you installed lm-sensors and gkrellm?
The only temp you should really be concerned with is the higher temp coming from the pump and that could easily be set to change the fan speed. Using the higher temp would be directly affected by the cpu temp, while using the delta would be imprecise if room temperature varies.
The cpu fan connection should also control fan speed based on cpu temp and AFAIK that is handled by bios.

If you installed lm-sensors then a script to monitor the sensors output could be used to control your fans as well.
I use fedora and I always keep a gkrellm window in the corner of my desktop so I can see fan speeds and temps at a glance

update:
I just checked the data in /sys/class/hwmon/hwmon7/ on my system (which gives the cpu info) and found that there exits a file tempX_input for each core. Doing cat of each those gives me the raw data for the temp input of those sensors and it would be trivial to calculate a delta between 2 sensors and use it for fan control. Just a little writing of a script would be required.

Yeah, I have them installed, aswel a third party driver for my corsair commander pro(https://github.com/MisterZ42/corsair-cpro). I have a custom loop with both my gpu and cpu. My pump is allways at max. I find it more effecient to focus on my water temp and not the components. Also as my room gets heated I dont want the fans to go up with it. I think what im looking for is a script. I tried a while ago. Doing some cat on files piping to do some arithmetics, but I didnt succeed and now my head feels kinda heavy x). also how do i make this a virtual sensor appear as a source so i can just pwmconfig?

So I found this simple command that gives me the delta: paste -d- /sys/class/hwmon/hwmon3/temp2_input /sys/class/hwmon/hwmon3/temp1_input | bc -l
Now I need to figure out how make it appear as a sensor