Can you flush with un-ph'd water

I think I need to do another flush to my plants. But I have 8 plants so I will have to ph so much water. Is it ok to flush with water straight out of the tap and then give it say a litre of phd water at the end?

Can anybody tell me if this will do more harm than good?

Flush with ph'ed water otherwise the plant can get a shock from it going from what it has been at the tap, back to what its supposed to be. Possibly other stuff too, but i wouldnt know because i havent tried it.

PH is one thing... PPM is another. I would never use tap water period due to it being between 550-600ppm (in my area).

Lastly, if your soil was mixed with dolomite lime than PH wouldn't be a concern.