The test strips don't give an accurate reading, try and get the test that uses drops. I agree, PH down does not work very well and you would have to use it for every water change, and PH swings are dangerous for your fish.
If your ph out of your tap is that high you can add a piece of driftwood to your tank or peat moss in your filter would lower it a bit, but I would bet that your test strips are wrong.