balast tanks filling with water while cruising?

I was out for the first time sunday in my new boat. It's an 04 mobius ls with front and rear ballast tanks. My question is while I was cruising I noticed the boat seemed heavy and I checked the bag in the ski locker, It was, opening the door on it's on, FULL. The pump was not turned on. The rear tank was also full. The pumps were not turned on, and As soon as I set them to empty they did what they were supposed to. Once I turned the pumps off the tanks started filling back up? Am I missing something here. I found a manual cutoff valve right in front of the water pump for the ballast tanks, Does this need to be closed when cruising?? Any help would be appreciated.

There should be a valve before the solenoid valves for the ballast tanks. Just flip the switch the other way and they will stop filling while you are cruising. I had the same problem when we pick up the boat new. Just a simple flip of a switch. It is addressed in you owners manual if you to see a picture.