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.
View as List Keep Your Salad Greens Safe. Raw leafy greens, such as lettuce and spinach, are delicious and have a lot to offer as part of a healthy diet. But some experts now call them the riskiest foodâmore likely to be contaminated with harmful bacteria than even hamburgers.