On the last page in one of the pic did you put the heater into the gravel or was that something else?
If I were you, I wouldn't have your brother come over when you are gone. Fish can easily go up to a week without food. Feed up until you leave, do one last WC and go on your trip! There are usually more problems when you have someone watch your fish that doesn't know what they are doing. If your bro has fish then thats a different story.
Start cutting them back bit by bit before your leave?