aquarium salt, a backup heater(better to use 2 small ones than 1 large one incase 1 breaks) pima and melafix, aquarium silicone, a hosptal tank or clean rubbermaid tote, extra filter media, a python or generic waterchanger, a master test kit(an ounce of prevention is worth a pound of cure) stress coat/dechlorination, a backup air pump with check valves, extra airstones, and if your area is prone to power outages, a generator will keep you and your fish happy. If a generator is out of your budget, you could buy a power inverter for a vehicle and use a car as a generator. make sure you get appropriate wattage.