LOL, far from it. Tap water contains chlorine, flouride and other additives. Rainwater is the best water for your plants, distilled comes in second. Tap water is the last thing I would use on my plants, as my water is hard. Tap water from a water softener has too much sodium.
If you have no choice and HAVE to use tap water, let it sit for 24 hours to allow chlorine to evaporate.