my oscar tank was a constant ph level of 7.3 (light green) while my father has a level of 8.2 which is normal and what do we do to fix these levels as I think that 7.3 is too low and 8.2 is way too high
Oscars are quite tolerant to a range of pHs as long as that pH stays stable. Both of you leave your pH as it is and you will both be fine. If you start trying to raise or lower the pH is will result in fluctuations which your oscars will not like.