Either will work. If you are worried about the chlorine in the tap water just let it sit out overnight ot in the sun for a few hours. The chlorine will break down. -Bill
I believe the chlorine doesn't break down it evaporates.. which is why it is important that you let the water sit out overnight in an uncovered container. For the long term though, distilled water is the best for purity and there are plans on the internet to make cheap solar distillers yourself. Because of the evaporative nature of chlorine you can absorb 10X or more chlorine in a hot shower than you would drinking the same water all day! Good luck Fiend!
Just use tap water. Let it sit overnight in a bucket at room temp, and you'll be fine. I use some toilet paper - two layers - seeds - another two layers. Wet paper so much that there will be just a bit of extra water in the plate (or so). Put it in a plastic bag. Not airtight just put it in there. Put it somewhere room temp or slightly warmer. Living room will do it. Good luck (although you don't even need it for this. They'll sprout) Have fun