Hi everyone. I am a newbie here . We drained and painted our 22,000 g guinite pool the past week and have filled it back up with tap water and are ready to balance the water. Took a water sample to the pool store and the pH was 6 and the total alkalinity was 40. They said we needed to put a liter of metal free in first, wait 2 hours then add 3 lbs of soda ash. They said we needed to do this first before adding any chlorine or it could stain the pool. I wanted to check with you pool experts if what they told us sounded correct. Thanks!!!!!