I had a similar issue a few months back. The apex decided to turn everything off and i didn't notice it till 12 hours later. Lost seven fish and almost lost my prized fish, a 9 inch fowleri tang that i had for two years was on his back gasping for air. My husband rebooted everything and we called Neptune directly. They walked is through resetting everything back up. Worked fine for a day. Same thing happened on day two, but we noticed it after an hour. Called Neptune again, they accessed our computer and went into the apex unit and it blocked them out. ??? So the guy told us to send in the base unit. Sent it in and was told that it was an internal electrical failure that was "not uncommon". Was fixed and returned within a few days for $60. Haven't had an issue since. Call Neptune.