Here is what I do for nice clean water....
Needed: 5 gallon collapsable water container. Any campin place has them.
2 piece funnel with flexable spout. Any Autoparts store has these. Used for tranny fluid.
After cleaning the tank after winter with bleach and a flush or two, you can add water by:
Going to the supermarket which surely has a filtered water machine outside. (some areas of the coutry may not have these yet but most do)
Use your water bag and have 5-7 quarters ready for the machine ready. (25-35 cents a gallon) Stick your bag in and fill it up.
Carry it back to the van. Use your flexy spout collapsable funnel. (this is a must have item for any van) I have a 10 " piece of line connected to the rim top of the funnel. When the funnel is inserted in the water hole, use the line to tie the funnel in place by tying it to the mesh of the small storage area. Now pour the water slowly in the funnel allowing for proper venting. 5 gallons goes in pretty fast.
Repeat if you need more water. Now you have fresh spring water in the sytem and it stays fresh as long as you have cleaned your tank well. Add a few cap fulls of hydrogen peroxide to keep things sterile longer.
Deflate your bag and put it where ever it fits, and disassemble the funnel and stick it back in small cubby hole.
Done!
Paul
over 430 camping nights and counting.......
95 EVC