Testing the pH of tap water with Simplex Health pH test strips

Easy and simple to use pH test strips for testing the pH of water

Water pH test strips with a range of 0 to 14
pH indicator strips are non-bleeding, colour fixed strips
With easy to read colour chart on the box
Each strip has a four-colour indicator chart for increased accuracy

Suitable for: fresh water samples, including water from taps, wells, springs, boreholes, ponds, lakes, rain water as well as aquariums, swimming pools & spas

Contains: 100 tests

Testing Levels: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14

Test Procedure: Soak the test strip in the test solution for half a second and compare it with the colour chart.

[fantasticpaki]

much simpler than ph digital meter and its calibration

[joeasher]

I have the 4.5 to 9 simplex ph strips (they have two indicator pads, rather than 4 for the full range). I'm trying them out on rainwater and the end pad (orange when dry) reads as 6.75, where the other pad (yellow when dry) reads as 6. I could average it out and say that it must be 6.5, but it doesn't match 6.5. I've had much wider results with tap water (a difference up to 1.5 ph). Should I be taking an average or is this a sign there is something wrong with the particular strips themselves?