If there is a bathroom across the hall, you can use this. I've used a darkroom without running water for a while - but I won't lie to you - running water is MUCH more convenient and most of all: saves time. It also becomes more important once you start focusing on local bleaching (although you could still do this elsewhere) and really helps when it comes to cleaning trays and the like after a session. The drudgery of carrying water and trays back and forth tends to get to people after a while.
Originally Posted by Stephen Prunier
What are your adjacent rooms? If the bathroom is adjacent or sharing a wall - you can gain access to the hot/cold water supply and tee from there. Most hot/cold supplies are 1/2" or 3/4" copper routed through walls or routed under a crawl space and then vertically run to a fixture. The point being that if you can find them, you can use them.
Stop worrying about grain, resolution, sharpness, and everything else that doesn't have a damn thing to do with substance.