Note any water color or odor. Water pH can be measured using test strips. These are extremely popular with younger students. Water Temperature Temperature can be measured at the surface and at other depths. Note that streams might have very different temperatures in different areas, for example in a deep hole versus a shallow, sunny area.
Thermometers break easily, and older ones are made of glass containing toxic mercury.
Water Clarity Water clarity is often measured using a Secchi disk. You can easily make one using a white plastic disk, such as a margerine tub lid or a plastic plate. Draw two perpendicular lines to divide the plate into quarters. Color two opposing quaters black with a permanent marker. Punch a hole through the center of the plate and pass a small rope or heavy cord through it.