"What is one thing you can't live without?" asks Brandon Clay and Ron Rowland. "Take away that glass of cool, clean drinking water from your diet, then it's a matter of days before you dehydrate and die." ons

In All Star Investor, they explain, "Water is essential to our survival." And for investors, they add, "Powershares Water Resources Portfolio (ASE: PHO) is a perfect play on the global demand for water technology."

"The essential nature of water is the same for the 6.67 billion people on this planet. With Latin America and Asia entering the modern world at an unprecedented pace, water is becoming even scarcer.

"Improving diets and growing industry have pushed this diminishing resource further from the reach of many people. Yes, people are still drinking water, but at what cost?

"Water covers most of our planet. Still, less than 2% is fresh water. That makes water a limited resource. Consumption is growing with 6,000 cubic meters per inhabitant used every year. That's the equivalent of draining Lake Superior – the biggest lake in the world – twice. Since the water cycle is not replenishing growing demand, water sources are being depleted.

"We've been tracking the water industry for a while and it's been crystal clear that water is an area we want to dive into," says Toby Smith in his ChangeWave Investing. Here, he looks at a water-focused ETF.

"Water is often taken for granted, but that is changing. A combination of global economic growth and years of neglect are leading to a tidal wave of demand for water infrastructure and various technologies.

"It's forecasted that by 2025, almost two-thirds of the global population will live in countries where water will be a scarce commodity. Climate change could exacerbate the problem. Clearly, water issues cross all boundaries.

The water industry combines the best attributes of a good defensive strategy coupled with numerous 'offensive' plays. From a growth perspective, spending on water projects at all levels is on the upswing due to years of infrastructure neglect and under-investment.

"One great way for all investors to participate is by investing in an ETF with a water focus, such as PowerShares Water Resources (NYSE: PHO).

"The beauty of this water ETF is that it gives us exposure to each of the companies that were highest rated in our survey (comprising approximately one-third of the PHO holdings). PHO also has a well-balanced portfolio, with no single stock representing more that 4% of the total. IN our view, it's clear that the water industry will see above-average growth well into the future."

Each day, Steven Halpern's TheStockAdvisors.com offers the latest market commentary and favorite investment ideas from the nation's leading financial newsletter advisors.