1-10 volt pumps and level sensors

Hello,
I have 3 pumps 1-10volt
one for the skimmer, one for media rectors and one for return pump.
I know that I can connect them and give them the volts to keep running at minimum, maximum,at night or feeding pause.
but I want to connect them with the level sensors, eg. the speed of the skimmer I want fall to a minimum when the level in the sump goes up (level sensor 1).
the speed of return pump goes to minimum when the level in the aquarium goes up (level sensor 2)
and the speed of 3 pumps fall to minimum if the sump water level goes down to protect the pamps (level sensor 3).
I know I can use the powerbar but i dont want to power off the pumps and i dont have 3 free sockets.
is there any way?
thank you very much!