Your best option long term is to buy a RO machine. Theyre not too bad, for about $300 I got the machine and a 55 gallon drum to keep water in, including an air stone that will keep the water oxygenated. (Btw, leaving your water out is great for getting rid of some chemicals in the water but also lets the air escape which roots need) If you don't need that much you can get smaller setups too. RO machines are the machine that is used by Pepsi to make aquafina, the idea is that there is as little "stuff" in the water as possible once run through the machine. In my case the water will test having 0-5ppm (parts per million).

If you are doing only a few plants at a time, you can start with distilled or bottled if you would like. Buy the largest thing you can of quality water. Some grocery stores sell "0 water" this is basically RO water they bottle and sell. Home depot sells 5 gallons of absopure water for like $7 plus deposit or exchange, check what your grocery store does for gallons if you are in a large enough city to have a major sized store.

The key is the quality of the water, plants only absorb so much nutrition at a time from water, and having stuff in there that you don't want is inefficient, if you want to test your tap water (for how much "stuff" or ppm it has) you can get a basic tester for about $40 at your local grow store. Dont buy an expensive one, I use the basic one myself and its all you need for a ppm meter.

Im not saying tap water wont keep a plant alive, but just that quality counts for how healthy your plant will be. Healthy plants produce larger and higher potency buds.
ddxsinxcosxdx Reviewed by ddxsinxcosxdx on . What type of water should i use?? What kind of water is best to use for plants? i have been using tap water and letting it stand for 24 to 48 hours before i use it and also so it can get to room temp..............can you use spring water? or can you use distilled ? but if you use theys do you have to add anything to them ? Or is tap water just fine enough? I dont know if my tap water is good or not when i have sprayed onto my plants after it dries i have noticed the leaves have a little white residue not alot just barley could Rating: 5