I truthfully pay little attention to ph. I believe my tap water is a little high, but I've never treated it. Sunken driftwood probably brings it down some, but Alpine newts are pretty adaptable.
I have seen newly morphed newts climbing up air line, so it's not unreasonable to expect them to squeeze out whatever hole the tubing comes into the enclosure. I seal mine with duct tape.
I hope they do well for you. They just might come to be your favorite amphibians of all time.