A little more help needed, please.
Today @ 11am: FC=5.5, pH=8, CYA=55, TA=75, CH=450. FC has been holding steady @ 4-6 by adding 182oz. bleach daily.
I have been adding cyanuric to raise CYA to target of 80. Last addition was 4 lbs. on 6/28. Readings went from 35 on 6/27, 60 on 6/29, 70 on 7/2, 70 on 7/3, 60 on 7/4, 55 on 7/5.

Am I doing the test wrong? I know it shouldn't drop. I have not backwashed. Added about 3-4 inches of water that disappeared very quickly. Suspect I may have a leak near surface. I have also been adding muriatic acid & aerating to lower pH & CH. pH has been @ 7.3-7.6 but I ran out of muriatic & it went up to 7.8-8.

CH went from 500 on 6/28, 450 on 6/29, 400 on 7/1, 500 on 7/2, 450 on 7/3, 400 on 7/4, 450 on 7/5. I am using the 10ml. size test. It seems like the color starts to turn purple-ish at about 15 drops, but doesn't turn blue until 16-18 drops? Again, am I doing it wrong? I know I need to add more muriatic & cyanuric. What else do you recommend? I have set my targets at FC=5-10, pH=7.4-7.8 (after CH goes down), CYA=80-90, CH=200-400, TA=80. Are these reasonable targets?