"We all need more buckets" - Prepper Mantra
http://fivegallonideas.com/stores-hand-five-gallon-buckets-free/I've found free buckets at the deli counter/baker section of Sam's Club. This NOT the only source of food grade buckets.
You may want to buy "Gamma Seal" lids which give an airtight seal on regular 5 gallon buckets Plus make it much easier to open the buckets.