Common Chemical Tests
| Temperature | Acidity | Dissolved Oxygen (DO) | pH | Aluminum |
| Flow | Alkalinity | Total Dissolved Solids (Conductivity) | Iron Ferrous | Manganese |
Total Dissolved Solids (TDS)
Total Dissolved Solids (TDS) refers to the ions and other particles dissolved in the water that you can't see. Be careful not to confuse this test with conductivity, which measures the electrical conductance of water. The two are closely related, but no the same. The major components of TDS are bicarbonate, calcium, sulfate, hydrogen, silica, chlorine, magnesium, sodium, potassium, nitrogen, and phosphorus. It is essential to maintain a constant level of these solids. For example, a sudden increase is salt from brine leakage of a mineral extraction pond can have a devastating effect on the aquatic life. Streams containing flow primarily from groundwater have a high TDS level as minerals leach into the water as it filters through the rocks. Storm water is usually low in TDS.
Other tests, including and/or in addition to those described above, may be appropriate for the watershed in your area. The indicators the were chosen as points of study while making your monitoring plan are a good way to decide what tests need to be performed.