Tarantulas can actually swim and won't drown as long as you provide a shallow water dish with low sides. Arboreal tarantulas don't always require a water dish. You can simply spray a mist of water on your tarantulas web weekly. Crickets are the best food source for your tarantula. They are cheap and easy to come by.
Adult tarantulas require a minimum of three to five crickets a week.
Larger species will also take mice. Spiderlings eat pin head crickets or will feed on freshly dead adult crickets. Spiderlings will not eat an entire adult cricket so be sure to remove the remains the next day. All invertebrates must molt in order to grow. Invertebrates will refuse food several days before a molt.