reservoir air stone question

i recently got a 18 gallon tote to use as a water reservoir. i just use it to let my tap water sit out for a couple days to let chlorine and what not evaporate before i water my plants with it, but my question is do i need to but an airstone in the bottom to keep the water aerated while its sitting out? i normally only put between 5 to 10 gallons at a time, and am wondering i need an airstone or not to keep the water from getting stagnant, thanks

It will quicken up the evaporation of Chlorine by adding a airstone.. it will also add oxygen to the water which the plants love.. if you didn't have a airstone it would go stagnant after a while in a hot/humid environment.. I always have a airstone in my res.. always.

I think it helps. Still standing water is never good, keep things moving with the air stone...you only need a small pump , maybe $7, and it will run that reservoir and even much bigger resovoir if you ever up-size your system. Good luck to ya

Chlorine evaporates out of water very quickly, like in a matter of hours.

alright cool thanks, what do you guys think the longest i should let water sit out if i have an airstone in it, or does it not matter?