1 In general, the total dissolved solids concentration is the sum of the cations (positively charged) and anions (negatively charged) ions in the water. 2  Parts per Million (ppm) is the weight-to-weight ratio of any ion to water.  A TDS meter is based on the electrical conductivity (EC) of water.
Collard greens may be worth considering for health additions to your diet. These dark-green leafy vegetables provide iron, vitamin K, folate, calcium and the antioxidants lutein and zeaxanthin. They may even help you prevent gout or reduce your symptoms when you eat collard greens in moderation as part of a healthy diet.
Collard greens have been eaten for at least 2000 years, with evidence showing that the ancient Greeks cultivated several types of collard greens, as well as kale. Southern United States Edit. Collard greens are a staple vegetable in Southern U.S. cuisine. They are often prepared with other similar green leaf vegetables, such as kale, turnip greens, spinach, and mustard greens in the dish called mixed greens.