8.8 is fine. In fact, for most applications, it is excellent. I would not mess with it at all. The beneficial bacteria that create your tank's cycle actually do the best in a pH that is between 7.5 and 8.6 - so you are much better off at 8.8 than at 7.0. Being at 7.0 is also on the bottom end of where I would want to be,
unless there was a very robust kH buffer in the tank to hold that pH solidly.
The only problems that can occur are most commonly when medicating your fish. Ammonia is more toxic in higher pHs, as is postassium permanganate. Chloramine-T is the opposite - more toxic at lower pHs.
If your kH is good, and your pH is 8.8 - and I suspect the kH is fine if your tank matches the tap water - then you are good to go. The fish will do just fine in that. Just keep it consistant and they will do GREAT!