moved in last august, drained and repainted pool. fresh fill started with tri-chlor tabs to get cya in range...after 3tabs and about 3 days i had 3fc 3tc ph of 7.2 and cya less than 30. tested today (day 5) and had ph 7.4(added about 12 oz by vol of soda ash) and no chlorine. tabs were disolved...