If the water turns red If the water turns red, it is a clean sign that the pattern is acidic. Do RO filters boom the acidity stage of water? If you filter out alkaline minerals, you'll be left with water that is barely acidic, that is regular. As a matter of fact, you will get the equal effects no matter the form of filtration. Since the water is barely acidic, it's going to now not damage your health. No be counted...