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 in chlorine adder. i added 4 tabs to it to continue the path i am on... at what point should i switch to liquid bleach to keep cya in range and how often does it need to be added as a rule of thumb, i know it depends on test results but i have no idea what to expect(daily, weekly). Also CH is 70ppm and ALK is 60ppm, how critical are these?