Of all the water parameters for aquariums, pH seems to be the one that people worry about most. It's really not as important as people think though.
There hasn't been a lot of research on the pH needs of amphibians, but they seem to readily adapt to a wide variety of values. As long as their pH doesn't shift quickly they should be fine and not have any problems.
A pH of 7.5 sounds just fine. It is slightly basic but that also means the water is probably buffered, which is a good thing. If you have buffered water it is harder to change the pH.
If I remember correctly, Jennifer has been breeding and keeping newts at a pH of 8. I personally have kept my newts for two years at a pH of 8.3. I live above a limestone aquifer so I have very hard alkaline water.
In summary, your pH is fine. It is far more important to pay attention to Ammonia, nitrite and nitrate levels in your aquarium.
