(CBS) — Federal investigators are looking into Real Water, after the company’s bottled alkaline water made several people ill. Real Water issued a voluntary, nationwide recall but many questions remain.

Real Water’s founder Brent Jones explains the benefits of his company’s bottled alkaline water in a YouTube video.

“…including assisting with better cellular hydration and creating an antioxidant effect on the body,” Jones says in the video.

They sold the water nationwide, offering home delivery of 5-gallon water bottles in Las Vegas to people like Ryan and Arika Carrier.

“It’s advertised quite a bit in Las Vegas. They have the trucks around town that say Real Water on it,” said Ryan Carrier.

Reporter Anna Werner: Why this particular water?
Arika Carrier: “We thought we were getting the best water that our family could drink, having this alkaline PH water.”
Ryan Carrier: “And I like the taste of it. I did.”

Their 2-year-old son Finn and 5-year-old daughter Hera drank it too. But last year, Hera started getting sick.

“Constant complaining, ‘Mommy, my tummy hurts. I don’t feel good,'” Arika Carrier said.

Then in November.

“She got really violently ill. She had stopped eating at that point because all she was doing was throwing up.”

Her son became incoherent. They rushed her to a local hospital.

“You don’t know what’s going on with your daughter. You’re putting her in the back of the car, limp in the car seat. It was excruciating, excruciating,” Ryan Carrier said.

There, doctors told Arika the 5-year-old’s liver was failing. And what’s more, they couldn’t treat her there. She would have to be life flighted to Salt Lake City for a possible liver transplant.

“It’s absolutely like going into shock, you know, thinking that your, your 5-year-old might need a transplant,” Arika Carrier said.

“Not many things make you fall on your knees in life, right? We fell to our knees. Right? We all prayed,” Ryan Carrier said.

Their prayers were answered. Hera avoided a transplant.

But it wasn’t just their child. Over just 11 days, health authorities said five children between the ages of 7 months and five years became ill — all at risk of needing liver transplants. Health officials say the “only common link between all the identified cases” was “the consumption of ‘Real Water’ brand alkaline water.” Six weeks ago, the company announced a nationwide voluntary recall.

CBS wanted to ask about what happened to those children and went to the company’s office but it was empty. There were a few trucks sitting outside.

Real Water later declined CBS’s request for an interview. But online, founder Brent Jones said this:

“We’d like to express our deepest sympathy and concern over the events that led to the inquiry…”

In a video posted to his website in March, Jones apologized to his customers.

“…we have issued a voluntary nationwide recall of all Real Water until the safety of our product is clearly established.”

“If I thought s– we were makin’ people sick, I wouldn’t have made it,” said Casey Aiken.

This videotaped deposition of a former Real Water employee, obtained by CBS News raises serious questions about how they made the water last fall.

Aiken, who was hired after working for strip clubs, said he had no experience in chemistry and only a couple hours of what he called “hands on training” but he was the one in charge of mixing liquid concentrate into the water here at the company’s officers outside Las Vegas.

Question: “As we sit here today you don’t have any idea what was in the liquid concentrate?”
Casey Aiken: “Not a clue.”
Question: “OK. And you don’t know where it came from?”
Casey Aiken: “Not a clue.”

Aiken said in September or October, he was mixing a new batch in the tanks, and got a low reading on a meter he was using to measure the water’s alkalinity level so he called his manger, Brent Jones’ son Blaine, to ask what to do.

Question: “And he told you to add more concentrate?”
Casey Aiken: “Correct.”
Question: “And he didn’t tell you how much?”
Casey Aiken: “No, he didn’t tell me how much.”

Aiken said he decided to add two and a half more gallons of the concentrate to the water.

Question: “You do understand that if you potentially add more concentrate than you — you usually use that there could potentially be a problem with the water, right?”
Casey Aiken: “I wouldn’t think so.”
Question: “You would think so?”
Casey Aiken: “No, I wouldn’t.”
Question: “OK, but you don’t know what’s in the concentrate.”
Casey Aiken: “If I’m putting into somebody that’s ingesting it, I would think that it’s safe no matter what. That’s my thought.”

The FDA is still investigating but consumer advocates say the situation say the situation shows the need for stronger regulations for bottled water.

“It really is sort of the Wild West out there with a lot of smaller bottlers facing very infrequent, if any, inspections and testing by the government,” said Erik Olson with the NRDC.

That’s why the Carriers say they’re speaking out.

“We want people to be aware,” Arika Carrier said.

“This can’t happen to any more people. It’s happened to enough. It’s happened to enough,” Ryan Carrier said.

The Carriers have filed a lawsuit against Real Water. In a court filing, the company denied the allegations. But health authorities say all of those young children were able to be brought back to health without liver transplants.