The water pressure and water temperature are both major issues with RO filters. The RO membranes and the bypass valves, which create the back pressure with pushes the water through the membrane require 50 psi of water pressure and 50 degree C water or higher to get the rated value of output. A water pump and electric solenoid for auto shutoff of pump would cost $125 to $150 or a little more depending on where it was purchased. If you checked the amount of water coming out of the RO drain you would probably find your putting out over 7 to 10 gallons of waste water for every gallon of RO water produced. That is 2 to 3 times what it is supposed to be. Heating the water up as suggested would help your output, but your RO water would still be made at a higher cost than buying it. I live in Alaska where the water runs at 34 to 36 degrees all year round and where the water pressure is 25 psi. I have over $750 in my RODI water system. It only pays due to my using a lot of water, RO water is 50 cents a gallon hear, and it is convenient having it on tap. The other choice is to use a permeate pump, which cuts way back on waste water, but you still will not get the rated flow out of your unit. It also costs around $100.