I can't keep up levels

[spawn]

Tested today after work ,24 hrs,
Ca read @ 410 after being topped to 420 yesterday
Alk read @ 8.9 on a hanna after being topped to 9 dkh yesterday I find it odd that Ca is dropping faster even though it's added @ a slightly higher dose, again because of the salts, Ca is now added @ 144 per 24 hrs, & Alk is @ 138ml per 24. will check again tomorrow, but a 10 ppm drop in Ca is 56 ml more & the drop in alk is only equal to like 11. So ummm... like WTF.