I have a half acre fish pond 6 feet deep and I did water test my PH level was 6.5 and kit says probably need raise ph to above 7 any easy ways to do this
Liming is probably the best response. However, pH is not nearly as important as alkalinity. If that is measured much below 40, then liming is recommended. Below 20, it is absolutely necessary.
So I need to purchase another kit to test for alkalinity
yes. You could possibly get away with using test strips for an aquarium.
http://soiltesting.tamu.edu/files/waterweb1.pdfClick this link. Do the $40 test and you'll get a profile of your water chemistry. From that, you can decide what to do. Look specifically at Alkalinity to decide if aglime makes sense. If your alkalinity is at least 40 ppm, you don't need to do anything. pH of 6.5 is well within the window of "happy" water.