You may not have to be too concerned about what your PH is. If you have had your tank running for so long now, the PH is most likely where it has always been. What you should concern yourself with is possibly doing a
water change asap and see if that doesnt help. So many times our water perimeters could be off and our fish let us know when they start acting sick or out of the norm. When ever my fish start acting strangely I always do an immediate water change, as I know something must be wrong.
In your case, I cannot say for sure that is the problem. I have no idea when the last time you did a water change, how much and what size tank you have or what your water change routine is. If you can let us know.. hopefully we will be able to give you a hand.
ICK looks like little piece of salt over the fish. Finrot is another matter.