CLEVELAND -- Scan any store cooler and the choices may seem endless. But before you take that first sip, ever asked yourself why you've shelled out big bucks ... for water?

For an On Your Side consumer investigation, NewsChannel5 bought five different types of bottled water -- ranging in price from $1.39 to $1.79 -- and took them to Dr. Michael Nichols. The John Carroll University chemist tested the bottled, and tap water, to see if they were worth the money.

Bottle, Tap Water Lab Analysis

Nichols said, "They can vary in amounts of sodium, potassium, or chloride."

Nichols said all water is going to have different minerals based on how it was treated and where it came from.

"As water percolates through the soil and comes in contact with limestone, it will have a lot of dissolved calcium and magnesium in it," Nichols said.

Fiji and Evian, two of the higher-priced waters, are expected to be high in minerals, or harder, because they come from natural waterways.

And Smart Water, another expensive option, claims to be fortified with electrolytes.

Nichols put the five bottled brands, and a sample of Cleveland tap water, through two tests.

After the samples were evaporated by flame and sucked though straws and columns, Nichols shared the results.

Nichols said, "Probably the only surprise was Aquafina."

That's because Aquafina shows almost no traces of minerals at all, meaning it is almost distilled.

Other surprising results came from Fiji, with 17 milligrams of sodium per liter, and Evian, with 87 milligrams of calcium.

As for the Smart Water, Cleveland Clinic dietician, Amy Jamison-Petonic, said it may not be your smartest choice for electrolytes.

Jamison-Petonic said, "The big ones we talk about are sodium, potassium, and calcium chloride."

Smart Water had no sodium and eight-times less calcium than our tap water.

In fact, Cleveland's water had more electrolytes than Smart Water, Dasani and Aquafina.

But Jamison-Petonic also pointed out, "People might not realize you can get all the electrolytes you need from a good healthy diet."

She said buy whatever water you'll drink but don't buy into the hype. Because at the end of the day, water, is water. That knowledge alone can save you money.