Water
Some people swear by distilled water. It usually has a ppm of 10 or less. Or you can get you a couple of 5 gallon bottles and go to the local walmart and fill them with reverse osmosis water which is almost as clean as distilled. And if your rich you can buy an osmosis filter for your home. They waist allot of water and need the filters changed regularly but the water sure does taste good. And you will have as much as you want on hand. Like I said it waist allot of water so expect to see the water bill go up.
I use plain tap water.
The chlorine in it will burn the tips of the leaves. I usually let my water sit out for a couple days to allow the chlorine to dissipate. You can also use those drops for the fish tank. I hear that works too.
One thing thats helps is to keep a fish tank pump bubbling in your water so it doesn't get stagnate. Try not to leave fertilized water laying around for a long time. Molds will grow and use up nutrients. And it just looks bad. But if you have a hydroponic system you will need to keep a reservoir. So just keep it out of the light for the most part. Also keep an air bubbler in your reservoir to keep oxygen in the water. The roots will like this.
These are my water containers. I usually keep fresh clean water in one and when I decide to water I fill up the other can so I can mix my solution. I only use what I know I will need. So I dont ruin my solution from sitting over time. Notice the air pumps and I have a submergable pump/hose that I feed with.
Here is an osmosis filter.
