same thing happened to my first grow!i was leaving the house for a weekend.fri-sun.filled up the AG rez to the top..i get back and they done drank all the water and half dead.too far to shake back,,Thats why i upgraded to a bubbleponics system..i just check it once a week and change water once a week.LOVELY!
If you have to leave town, maybe try cutting off some of the lights, to reduce heat and water consumption...