CSI is a complex calculation with a lot of factors. Temperature, pH, TA, CH, Salt among others. You can play what-if games in Pool Math with the result by changing one or more items ("What if my temp went from 50 to 85?",or "What if my CH was raised to 300?", etc).
Is the chart you are using like the one attached? Note that the Salt Water section has a broader range than the one above that is without. This just to reflect the consistency a SWCG provides when it is running. If it is not running, just keep your CL at the top of the range for your level of CYA, which is the same for both sections.
CYA recommended levels for salt pools are higher, see this thread for "why": Why such high CYA recommendations for saltwater pools?
But your level of 40 is not critical at this time of year (less CL loss due to sunlight), so you can postpone building up the CYA if you want, until warmer weather.
Finally - TA is slow to drop. As in very slow. Won't happen in a day or two. A high TA, such as yours, will raise the pH. Aeration also raises the pH (with no effect on TA). Adding acid to drop the pH will also drop the TA a little bit. Some try to accelerate the process by dropping pH to 7.2, letting it rise to 8.0, and hitting it again. But even that is a once a day test and add thing. Eventually, when the TA gets in the lower numbers (<70 ish) the pool will begin to need less and less acid. If you run the aeration a lot, you may eventually need to build up TA a little. But for now, best is to manage pH only, and only occasionally check TA.
Note the interplay with CSI I talked about before! Depending on all the other chemistry in that calculation, you may elect to have your own "custom" TA level to keep CSI in range...
Is the chart you are using like the one attached? Note that the Salt Water section has a broader range than the one above that is without. This just to reflect the consistency a SWCG provides when it is running. If it is not running, just keep your CL at the top of the range for your level of CYA, which is the same for both sections.
CYA recommended levels for salt pools are higher, see this thread for "why": Why such high CYA recommendations for saltwater pools?
But your level of 40 is not critical at this time of year (less CL loss due to sunlight), so you can postpone building up the CYA if you want, until warmer weather.
Finally - TA is slow to drop. As in very slow. Won't happen in a day or two. A high TA, such as yours, will raise the pH. Aeration also raises the pH (with no effect on TA). Adding acid to drop the pH will also drop the TA a little bit. Some try to accelerate the process by dropping pH to 7.2, letting it rise to 8.0, and hitting it again. But even that is a once a day test and add thing. Eventually, when the TA gets in the lower numbers (<70 ish) the pool will begin to need less and less acid. If you run the aeration a lot, you may eventually need to build up TA a little. But for now, best is to manage pH only, and only occasionally check TA.
Note the interplay with CSI I talked about before! Depending on all the other chemistry in that calculation, you may elect to have your own "custom" TA level to keep CSI in range...
. Thank you again!