Interested in Apex DOS module to feed Deltec NFP509 Nitrate Filter.

I currently have a standard Deltec Peristaltic Pump installed as the primary feed from my aquariums sump to the Deltec NFP509 Nitrate Filter. This is extremely slow and has no variable speed control. I'm starting to realize that I'm going to need something that can be controlled from a drip of water once every 3 seconds to what will be an small flow of water. I would also need a secondary pump to control the feeding of bacteria food source (a mixture of Vodka and freshwater) in small amounts starting at 1 ml and moving to above 8 ml twice or three times a day. My primary questions are will this work a varied dosing schedule twice or three times a day? Also while the maximum setting be enough to support a small constant trickle of water when I need to open up the flow after the bacterial colony mature?