This self-made rabbit watering system is an invaluable time saver. All you need is a bucket, some water feeder nipples from Ebay and 5/16″ silicone tubing (see links below):
An automatic water feeder like this keeps your water clean and prevents messes. I recommend to add 1 tablespoon of organic apple cider vinegar per 1 gallon of water to help with general health of your rabbits. This system can also be used for ferrets, chickens and other small animals.
Parts Available on Ebay: