Speed Variance on a 12v DC Hydro Unit

Hello , i have a 12v motor on a hydrolic pump that i need to vary the speed on. Right now it operates way to fast to be able to control it properly. i need something that i can constantly adjust the speed depending on the load. Any ideas what i can use, It also needs to be weather proof as it will be in the open.

Here is a video of the project i am building it just operates to quickly.
**broken link removed**

weatherproof is only the housing where you put the electronics in
IP 55 or higher is the one you want to use

what is the set up does it drive on a battery what does it supply do you need constand pressure

how big is the unit, what are the spects of your oparation with other words

probably it will be posibble to run it with a PWM circuitry

some more info Please

Robert-Jan


i can not see the video deu to my slow internet conection here so that's why i ask these questions