My fan speed won't go down

[Ewj71]

when i put the fan speed on the lowest my fans dont slow down video 

i have the magnetic spinning ones.

[c-attack]

I am not sure what you're showing us.  You are running the Quiet preset which has specific Temp X = Fan Y data points, though hidden from view.  Then you change to fixed RPM/% and apply the custom curve and all the fans drop.  Not all fans can run 200 rpm and those you changed dropped to their minimum possible speed.  You have some ML-Elite fans from the AIO that are capable of very low speeds.  Most other PWM fans don't go that low.

 

I suggest you go back to the custom curve and select the concave shape tool in the bottom corner, 2nd from the left.  This is a duplicate of the Quiet preset, but now you can see and move the individual control points.  Make sure the Sensor is set to H100i Elite Temp (coolant temperature).  That is proper control variable for the radiator fans.  You will be able to adjust the baseline and maximum points to fit your environment or preference.