According to ChemGeeks spreadsheet my water is balanced with these numbers

[chem geek]

ubalr1,

As you point out, your chlorine level is too low for your CYA and that is certainly something to deal with immediately.

Don't worry too much about trying to hit the CSI to a perfect 0. This has a LOT of leeway, much more than I show in the spreadsheet. There are some users who don't see cloudiness until they get to +1.0 -- others around +0.75. Not sure about the corrosion side, but I suspect it's similar. So my spreadsheet "red values" that start at +/- 0.3 are VERY conservative, before I got some real-world experience from users on this site. Basically, the general rule on this forum is not to use LSI at all and just be in the ballpark (unless you don't have grout/plaster/gunite in which case CH is not needed).

At any rate, your numbers will all change after a drain and refill to get your CYA down since that will lower most of your other numbers as well (except CH due to its high value from fill water). You could probably run with a very low alkalinity of around 50 which would balance nicely with your high CH and let you run closer to a pH of 7.5. You will also experience less pH rise since your water will be less carbonated at a TA of 50 (though that doesn't seem to be a problem for you right now).

In the meantime, you can try using Ben's Lowering Your Alkalinity post to get your TA lower. With a lower TA you will be able to move your pH more easily. In fact, I am a bit surprised that you aren't already seeing a rise in pH from outgassing carbon dioxide. Are you using a pool cover? You could accelerate the process by aerating (splashing, pointing jets up, etc.) -- following Ben's procedure by going even lower in pH first should have this process go even faster. You aren't in serious danger with 7.1-7.2 pH if you just want to let it slowly drift upward, but aerating should accelerate that.

By the way, have you measured the CH and TA of your fill water? It seems quite high so would be good to know what you're dealing with when you do a drain and refill.

Richard