The pH test kit from General Hydroponics has a range of pH 4 to pH 8.5 and lasts for about 200 tests. 1 fluid ounce of indicator solution included. Just take a half vial sample of the solution you want to test and then squeeze three drops of the indicator solution in the vial and match the color on the indicator chart. This is one of the most inexpensive and accurate pH test kits you'll find on the market that boasts such a large test range.