Buffering water during city water work?

[Alaya]

I currently have a small dilemma, and thought I'd seek some other opinions. My city is in the middle of doing some major work on our water supply sources. As a result, they changed up how much water is being drawn from where. Over the last couple of months, I've noticed my kh and ph have been dropping. Currently, my numbers out of my 55 g read as 150 ppm GH, 6.8 PH, and 80 ppm KH. Previously the numbers ran 150 ppm GH, 7-7.2 PH, and 120 KH. Water out of the tap is currently 50 GH, 6.4-6.6 PH, and 40 KH.

Now I normally would not worry too much about this, but since it seems to be a downward trend, and not stable, I'm more concerned. I should also mention that, due to last years forest fires, our current water supply is full of ash and other organics breaking down. I expect that to contribute even more once spring rolls around. 

Should I start buffering my water?

[lefty o]

it probably wouldnt hurt to toss in some crushed coral or a wonder shell.