Recently set up a Nuvo 20 and Im wondering what the evap is like? I only ask because int he morning I filled it up so the return was about an inch from the next chamber and by around dinner time it's down 2-3 inches. Just want to make sure I'm not doing something wrong and that that's just normal evap for the tank or I didn't fill it up intially to the correct level etc. Thanks in Advance.