Hi,
You can add a habbitrail water bottle to the rotastaks if you have a locking conector and one of the blue spagetti junction end tubes.
This is the same bottle as i have used
Habitrail Ovo Water Bottle-
Do you think this would be any good?
If your not sure what I mean I still have the peices i am going have to take a photo for ebay so I can post it here to if you want.
Kat