How do you check to see if you have kidney stones and what are the symptoms?

Plus, where I'm from they have "Hard water" which is build up of calcium deposits. I don't drink the water. I haven't bought a water filter yet for my faucet. However, I have a big thing of Kool-Aid mix that I want to drink, but I don't want to get kidney stones. Will one gallon of this water form up calcium deposits in my kidneys or is it something that happens over time long term?

Well, the clue that you have kidney stones comes from the excruciating pain. The most common type of stone is a calcium stone, but comes from a long time of calcium build-up. It is just as much or more related to dehydration, which causes the calcium in the urine to become concentrated. You will not get a stone from drinking a gallon of water. Think about it, people take Tums and other calcium supplements, and there is nowhere near the amount of calcium in the water.

You can get good information (including symptoms) at:
http://www.nlm.nih.gov/medlineplus/ency/...

Symptoms of kidney stones are things like flank pain (back area), pain with urination, frequent urination, sometimes a fever, some nausea and vomiting.
You can have kidney stones and they aren't a problem, they become a problem when they start to move out of the kidneys to the bladder, they can get stuck in the ureters and block the flow of urine which causes an even bigger problem or infection.
I wouldn't worry about drinking the water, the more water you drink is actually better for you. It keeps your kidneys moving and helps prevent stones from forming.