Stupid question but my installer never added any water to the ATO on my new Reefer 250 that was delivered on Tuesday and said it could wait. I heard a loud noise from the pump chamber yesterday and discovered that the water had evaporated to the point that the pump was half exposed to air. I added RO to the pump chamber yesterday so there was enough to cover the pump. Today I added more RO water to the pump chamber and also to the empty ATO as the water level in the pump chamber became low once again the pump was making the same loud noise. I am not sure how to properly adjust the small white valve on the tubing that goes from the ATO to the pump chamber, do you turn it clockwise or counter clockwise to open it and approximately how many turns do you do? I looks pretty flimsy and I am afraid if I turn it too far the top of this valve will come right off and I will have water shooting out of the tubing. How do I know that the float is working properly? What is the correct water level for the ATO?