I just buy 2.5gal water at the grocery store (on sale for $2.50) and reuse them.
Eight or more of these fit anywhere in truck or TM. Also great to have one at the outside table.
They can be poured into TM main tank when needed.
For frequent camping - invest in stronger water bottles, the grocery water bottles are flimsy.
20 gallons weighs 160 pounds.
Also consider weight limits on: TM / tires / hitch / tow vehical ...
SEE ALSO:
Adding a 20g Water tank
http://www.trailmanorowners.com/foru...ead.php?t=7491
Adding Second 20 gal Water Tank
http://www.trailmanorowners.com/foru...ead.php?t=3032
Adding a 20 gal. water tank to a 2004 3023
http://www.trailmanorowners.com/foru...ead.php?t=2353