The following ratings changes were generated on Monday, March 2.We've upgraded Calgon Carbon ( CCC), which provides services, products, and solutions for purifying water and air, from hold to buy. This rating is driven by the company's revenue growth, largely solid financial position with reasonable debt levels by most measures, compelling growth in net income, notable return on equity and impressive record of earnings per share growth. We feel these strengths outweigh the fact that the company has had lackluster performance in the stock itself. Revenue increased by 8% since the same quarter last year, and earnings per share rose significantly. The company has demonstrated a pattern of positive EPS growth over the past two years, though we anticipate underperformance relative to the pattern in the coming year. Calgon's debt-to-equity ratio is very low at 0.05 and is currently below the industry average, implying very successful management of debt levels, and its quick ratio of 1.2 illustrates its ability to avoid short-term cash problems. Net income increased by 105.4% since the year-ago quarter, from $3.8 million to $7.9 million, significantly outperforming the S&P 500 and the chemicals industry. Return on equity also increased. We've downgraded beverage company Hansen Natural ( HANS) from buy to hold. Strengths include its revenue growth, largely solid financial position with reasonable debt levels by most measures and expanding profit margins. However, we also find weaknesses including a decline in the stock price during the past year, deteriorating net income and premium valuation. Revenue increased by 3.1% since the same quarter a year ago, though EPS declined. Hansen had a quick ratio of 2.3, demonstrating its ability to cover short-term liquidity needs. Its 54.4% gross profit margin is rather high, having increased from the year-ago quarter, while its net profit margin or -9.2% is in line with the industry average. Net income fell from $45.1 million in the year-ago quarter to -$23.5 million in the most recent quarter, significantly underperforming the S&P 500 and the beverages industry.