You're thinking of chlorine.

Don't worry about it. Your tap water has to be REALLY REALLY REALLY bad to have to dechlorinate it before use. Like, undrinkable bad.

Thanks re: siggy btw!
stinkyattic Reviewed by stinkyattic on . Is it necessary to evaporate plant water? I heard before that if you want to take out something that the plants don't need all you do is fill a gallon of water or any type of water container and take the cap off and let it sit over night to evaporate something in the water. Is this necessary? :rastasmoke: Rating: 5