My ph on my 125g is generally a solid 7.9. I do not add buffers or anything as I think they can bring more problems than they solve. lol
Like mentioned above, if it's consistent I would just leave it be.
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.