Very nice design. Do you think the weight of the pump would wear out the servo a little premature? I was thinking if that would become a issue you could hang something directly above the pump separate from the servo arm to hold the wire directly above the pump. If done right this would help support the weight of the pump and also keep it free moving. A simple bracket could easily be made with some of the acrylic scraps. Lastly Have you tested using a apex to control the unit with the 0-10v output?