spring water isn't always the best water u can use, depending on the source the water can be full of calcium. rain water is a better option for u plants as it is always more acidic and when a plant is growing wild the plant will get most of it water from rain . anyway i use nothing but tap water and i aways have good results , to feed upwards on 30 plants mineral water would cost me a fortune. water is water at the end of the day its h2o no matter what way u look at it . leave ur tap water sit for 24 hours and the chlorine will be gone out of it .