Can Dosing Pump Unit change the speed (ml/min)?

Hi,

I bought on March of 2010 the Dosing Pump Unit (with 4 Pumps - PL0344) and I recall that the speed of the motors was fixed, the flow was at 60ml/min approximately.
On the new Dosing Pumps you can adjust the speed from 8-45 ml/min. (I think this alternates the DC current running the motor's, thus the speed can be changed).

I wanted to know if this is a feature that has been upgraded on the old dosing pumps (like mine) since I was off the hobby and now I am getting back with a
nano tank and I was thinking to put my old trusty Profilux 3ex on duty again.

no only the newer doser can be changed the speed.

Thanks!
I will find a way around to make it work in a nano tank.