Testing range is usually listed as 150-500 ppm
I used municipal water, ultra-filtered (paid separate filtering service company and tested water as mineral free) when filling up pool initially and had CH steady around 200 ppm month one and two (60 days later).
Without having added anything except liquids and CYA, it appears CH is slowly climbing, today at 250.
Is that to be expected while DB is curing?
Tests on 31.12.2010
Tests on 17.1.2011