pool set up

[flyfishiser]

My pool holds 170,000 gallons. My initial alkalinity level was 290 ppm. Adding muriatic acid had dropped that to 200, but now my pH is at 6.0. How low can I allow the pH to drop while working on the alkalinity? I added nearly 200 lbs of soda ash to bring the pH up to 7.0, but the pH didn't seem to change. With the pH so low, should I run the pump to filter the water or wait until alkalinity and pH are within acceptable levels? I am really in a quandry.