What Ph tester is better for fish?

I bought a an API Ph Tester which you add 3 drops to 5ml of water. and today i bought the test strips that test the Ph, Nitrate, Nitrite, Hardness, and Alkalinity. The test stripes are Jungle brand ( the stuff they sell at walmart. Now the API tester says my Ph is above 7.6 and the Jungle test strips say 6.8 - 7.0. What gives? Petsmart told me that the test strips i have are accurate. but yet i have such a difference in the Ph Levels. Any ideas or help would be great!