atiladahun,
If you really want to know the pH more specifically, try a High Range pH test. I use the liquid test kit from Aquarium Pharmaceuticals. It has two pH tests: one for 6.0 - 7.6, and one for 7.4 - 8.8. They are very simple to use. I'm sure there are other companies that make pH tests for higher ranges, as well, but I know of this one which works just fine. You can buy them as part of a master set which has many different tests, or you can buy the pH tests separately. Not very expensive either. Good Luck!
Kind Regards,
LogJam