Water pH test

Use a pH test to find out whether different kinds of water are acidic, basic or neutral.
Science content
Chemistry: States of Matter, Properties of Materials (K-7)
  • water from different sources: seawater, drinking water, pond or fish tank water
  • pH test kit that can distinguish between pH 6, 7 and 8

Test seawater for pH (it is generally pH 8 or basic).
Compare to drinking water (neutral or slightly acidic).
Compare to stream water (usually neutral), pond water and fish tank water.
Students might also want to test the pH of their spit (neutral).

Ocean water becomes more acidic as more carbon dioxide dissolves in it, which happens as the atmospheric carbon dioxide goes up.

Grades taught
Gr 2
Gr 3
Gr 4
Gr 5
Gr 6