I free feed Mazuri chinchilla. Other acceptable feeds: Oxbow chinchilla, .
There are also some acceptable rabbit feeds: Manno Show Pro Rabbit and Purina Show Rabbit
A second cut timothy hay, grass hay or timothy hay cubes, should be available daily.
Treats should be given vary sparingly: plain cheerios, plain mini shredded wheat, whole oats, rose hips. A very occasional raisin (I only use these if poo is looking small and hard)
Do not feed fresh fruits or vegetables. No sugary treats. Just because a treat is advertised as a treat for chinchillas, doesn't mean it is appropriate to feed them.
Water, I use filtered water, you can also use spring water. Do not used distilled water.