Is this municipal water safe if it sits out, check out this lab analysis.

It will be just fine, your plant will not complain! How they survived 100s of thousands of years in nature un-aided is a mystery!!

i don't see if that is % of mass or ppm listed... doesn't mattger. Don't let water sit out. That is without a doubt a net negative, even if it has a bit of chlorine in it. Two, if it's chloramine, then it is 100% useless to leave it sitting out as that won't gas off like chlorine will. Stagnating water is far worse than a tiny amount of chlorine that can't hurt your plantin anyway.. in face a plant uses some small amount of Cl. It's a trace element of note. If it is approaching 300-500+ppm hardness, that's when you want to consider using a filter of some sort. I dond't know exact cutoff.. my water is very hard at 250-300ppm. I never had an issue. I use the soft water now, lol.. which tells you a littl Na is no big deal over 3-4 months either... a mother plant you keep for years in 1 pot may be different. but relative to a grow cycle, meh... You are worried about think you cannot feel, taste or resolve in anyway and is not in anyway detrimental to your health if given to a marijuana plant you'll smoke/eat later. Chloring gasses off easily and also broken down very fast by sunlight... leave it out on back deck in sun for a few hours.. that'll take care of a good chunk if you insist upon it. do not leave water out for 24-48h before you use it. using it right away is probably fine, but it's a bad practice with no benefit that anyone can measure. lots of feelings on it, but no quantitative data to support it.