Affecting pH through Humidifier?

When I water my plants I give them filtered water that I leave in a container for a couple days. But in my humidifier I've just been using water from my bathtub faucet (I googled the pH of the tap water in my city and it said it was 8.0, my pH tester says the same) and I'm wondering if the pH from the chlorinated tap water could be causing a pH imbalance in my plants. (The one closest to the humidifier has been showing pH fluctuation)

So, could the pH of the water in my humidifier cause a pH imbalance in my plants or is it more likely something else? I don't have a soil tester but I mixed the shit out of the soil I'm using for all my plants and the others don't show signs of a pH imbalance. Should I give the one plant separate water from the rest that's been pH adjusted differently?

Thanks.

The pH wouldn't matter so much as the salt content of the tapwater. The fluctuations are the symptom and the salts are the disease.