Things to know about your pet chinchilla
Feed: Pellets and Hay
Basic Chin Dietary needs -
   Diet staples are pellets, hay and fresh water.
Simply stated, most pet chin owner feed their chins too many treats.  Changing foods often and offering to many treats can lead to a picky eater and cause many health issues including; shortened life expectancy, breeding problems, dry skin and poor coats.  Proper diet can prevent most vet bills and make your chin much happier.  We may feel the diet is boring, but chins thrive on monotony and routine. You should provided this for your chinchillas.
Pellets: These should be fresh, high quality CHINCHILLA pellets.  Brand is a personal choice.  If you must buy in bulk, freeze what you can in manageable amounts or share with a friend.  Most experienced keepers prefer a brand of pellets WITHOUT added treats or grains.  Being smart animals, chins will dig through to get the goodies and waste the basics.   If buying from a pet shop, demand a FRESH pellet that is packaged with NO treats.  Most manufactures claim full freshness for up to 6 months.  But I prefer no more then 3 months. Some keepers will use rabbit or guinea pig pellets.  While this will work in a pinch if the other pellets are very fresh, the bust substitute would be High Quality SHOW rabbit pellets. Some materials I have read state that there maybe other substances added to rabbit feed to prevent disease.  In the USA hormones, drugs and medication can not be added to feed, and I have been assured of this by a long time show rabbit breeder.  These warning must be for other countries.
Fresh Water: The water you normally drink is fine for your pets.  Most public approved water systems are fine - use this tap water for your chins.   If you use a Brita, Pur^ or other water filter and you feel it is better, then use it.  DO NOT use distilled water or soften water!  Bottled is not necessary either.  Chins will not drink the water if is has a foul taste or odor.  I have seen on another site that chins must have distilled, bottled water.  I know a person that did this over several years, and her chins had reproductive problems, health issues and small litters.  When babies were born, the females killed most, if not all, of the litter.
NEVER add ANYTHING to the water! Vitamins should be obtained from their foods, never from water. All animals must have fresh water at all times.  If your vet instructs you differently, then discuss that matter with them at that time.   Some keepers like to give various juices in a watered down state for various reasons.  Though I would not recommend this for most pet chins, if you feel you must do it, give a separate bottle but only for about 8-12 hours at a time.
Hay: The loose hay you select will have something to your location and local availability.  Timothy is often the preferred hay of most keepers, but Timothy, Alfalfa, brome and orchard grass may all work, depending on your situation.  Hay must be fresh smelling, dry and free of mold, mildew, weeds, toxins and insecticides.  Most owners buy the bags of hay at a pet shop or farm supply store.   If you are using larger amounts of hay, find a local horse stable that you can trust to provide hay that suits your needs.
Hay Cubes: These are compressed, high quality hay and often made of alfalfa or timothy/alfalfa mix.  Sometimes chins will eat hay cubes; others will just chew and shred them.  I try to keep these in the cage at all times.  These are available in pet stores, but more economical way is to check your farm supply stores or rabbit show suppliers.
Some chins may experience loose feces when consuming too much alfalfa, so if your pellets and hay cubes are alfalfa based, your loose hay should be timothy.
ALL Changes to diet, including pellets and water, must be done gradually over a minimum of 2-3 weeks.  Chins have very sensitive digestive tracts and rapid change causes complications that can be avoided by a bit of planning on the humans behalf.  You will need to know the maximum amount of food you will use in 30 days time, and how long it will take you to obtain your new food supply.  Also stay aware if you will need to transition from one brand to another.
This area has
more information on the 3 basic wild type of chins,a bit on the history of chinchillas exported from Chile and some sad facts about theamounts of pelts taken early on in history and the attempts to save the wild chins

Shortages
: Sometimes, for one reason or another, you may run out of hay or pellets.  IF you run out of pellets DO NOT panic and go out to buy the first thing you can find.  Just up the hay rations.  Chins can be maintained on just hay, good hay, for a very long time.  If you run out of hay, then pellets will do until you can get more hay.  It would be more harmful to the chins to switch foods quickly or back and forth.