> Do nepenthes need to be watered with distilled water like most 
 > other CPs?
 I do not consider using distilled water being advantageous for CP 
 leave alone its price. When using it some people advise to add some 
 tap water to it (I'd prefer to add some peat), because pure water 
 demineralizes the plants which is little beneficial to them.
 Unless you can collect rain water what would be best you can 
 improve your tap water unless it is very bad such as heavily 
 chlorinated, salty or very hard.
 One expensive way is to boil water and make thus some of the 
 hardiness of the water go to the bottom of your kettle. However it 
 can take quite some hours until the water cools down again and unless 
 you need only one pint a week this is not recommended.
 Another way to do this is to add some sulphuric acid (H2SO4) to the 
 water. I  did this for a while with no bad effect except for some 
 Sphagnum that didn't like it. However it can be dangerous to YOU to 
 handle such strong acids and last not least also to your plants 
 that will suffer from any mistake you might do in concentration.
 IMHO best is to add a handful of peat to about 10l (3 gal) of 
 tap water and leave it for a day or more. Filter off the peat and 
 enjoy your plants with the liquid. That's what I did for five years 
 with best results, however local water quality might have to be 
 taken into consideration.
 
 Finally, back to Nepenthes: This genus is exceptional in being quite 
 tolerant to the use of hard water! I know someone that waters his 
 plants with well water with no bad effects beside the white chalk 
 spots on the leaves. Even tap water might do locally if you let it 
 stand (degas) for a day or two. However it gives certainly a better 
 feeling to water them with better brands.
 
  Eric Schlosser