Dissolved Oxygen (mg/L):

How much oxygen is dissolved in your water. Generally, levels below 3mg/L are concerning.

Toxicity (% inhibition):

The degree to which your tap water is toxic. This includes high levels of bacteria, oils, metals, or treating agents in your tap water. Samples that give a % inhibition that is greater than -10% (negative 10) are considered toxic.

Turbidity (NTU):

A measure of cloudiness in water. Levels should not exceed 1 NTU.

pH:

Measures acid or base quality of water. A pH of 7 is neutral, below 7 is acidic, and above 7 is alkaline. Standard levels are between 6.5 and 8.5