Hi Redjeep,
It appears your ph/Alk has stabilized. You haven't had to add acid since 9/3 it looks like. I think you're over thinking the pH/alk thing. Measure your pH once a day. No need to measure again after chlorine addition (or any other addition, except acid of course). It's just extra data that mucks up the waters (no pun intended). Keep in mind as well that stability doesn't mean the number never changes, pH will change over time (within a couple/few days) even when pool is perfectly balanced, and will need regular adjustment.
The biggest contributor to a lack of precision (numbers all over the place) is inconsistency is sample size. Take care to make sure you measure the exact amount of sample every time. Using 11mls instead of 10 starts you off with a 10% error, not good. Just wanted to give you some food for thought. I know over time my measuring consistently every time has improved greatly and my numbers tightened up considerably. These tests are tailor made for the OCD crowd!
As mentioned previously, you also seem to have something else going on that is eating your chlorine, most likely algae. Your loss of almost 10ppm between 9/7-8 supports this, as does your earlier data with excessive chlorine loss. It looks like you need to SLAM. Keep in mind it is not a one time addition of chlorine but maintaining a high chlorine level over time (see FC/CYA chart) until the 3 exit criteria are met. It also has nothing to do with pH/alk, just coincidental.
The sooner you stop trying to tie these 2 issues together the sooner you'll get everything in line. They are completely independent.
It appears your ph/Alk has stabilized. You haven't had to add acid since 9/3 it looks like. I think you're over thinking the pH/alk thing. Measure your pH once a day. No need to measure again after chlorine addition (or any other addition, except acid of course). It's just extra data that mucks up the waters (no pun intended). Keep in mind as well that stability doesn't mean the number never changes, pH will change over time (within a couple/few days) even when pool is perfectly balanced, and will need regular adjustment.
The biggest contributor to a lack of precision (numbers all over the place) is inconsistency is sample size. Take care to make sure you measure the exact amount of sample every time. Using 11mls instead of 10 starts you off with a 10% error, not good. Just wanted to give you some food for thought. I know over time my measuring consistently every time has improved greatly and my numbers tightened up considerably. These tests are tailor made for the OCD crowd!
As mentioned previously, you also seem to have something else going on that is eating your chlorine, most likely algae. Your loss of almost 10ppm between 9/7-8 supports this, as does your earlier data with excessive chlorine loss. It looks like you need to SLAM. Keep in mind it is not a one time addition of chlorine but maintaining a high chlorine level over time (see FC/CYA chart) until the 3 exit criteria are met. It also has nothing to do with pH/alk, just coincidental.
The sooner you stop trying to tie these 2 issues together the sooner you'll get everything in line. They are completely independent.