Does it fit any 5 gallon bottle? Deer Park?

Thank you for reaching out to us. You can use most 5- or 3-gallon brand bottles with our dispensers with the exception of a few brands. Two that we know for certain are the brand American Maid brand and Glass bottles. The way the bottles are manufactured makes them incompatible with our dispensers due to the circumference and length of the neck. Please let us know if you have any other questions or concerns.