If it was a water issue, probably all your plants would be in trouble. Does the water taste funny out of the tap? Rusty or dark stains on the sinks and bathtub? If so, I'd be getting one of those screw on tap filters for your water. Use it for water for the plants as well as water that you're going to drink.
More likely your plant might need to be re-potted. Get a few sheets of newspaper, turn the pot on its side, and slide the plant out onto the newspaper so you can get a look at the roots. If there's still plenty of potting soil in there and it's dry-ish, then just slide the plant back in, and try going and putting it in the sink to soak in some barely-warm water. If the potting soil has dried hard like a brick, bust it up some with your hands before putting the plant back in the pot, then soak it.
If all you see are roots (well mostly) then go buy yourself a nice, bigger pot, some fresh potting soil and pot that baby up. Spiders like to be crowded in their pots, but they do get to a point where they need more room.
