wvmarle:
I think you're referring to this device which is linked to from that page.No word on whether it works with brushless motors (likely not), the specs do match those of the brushed motors that are suggested as option for that pump on the page you linked to, and it will work great with that type of motor.
Not exactly. This is to control the brush version of the motor. If you go down on my initial link you find a brushless version of the same pump and in this case they don't recommend the PWM module. Instead, they recommend to use a potentiometer and even show how to wired it. I only tried the brush version and it work with any PWM device (the one they sell is not very good). I never tried the brushless version.