So I have a question. Have seen several posts here over the past few days that state they have never calculated CSI. It was my understanding that's a rather critical index to know. Perhaps that's only true for the more newbies amongst us?
Playing with Pool Math as the temperature goes down, shows that CSI can quickly get into a corrosive state if you hold the other params the same as summer values.
The differences can be significant. Holding other params in check, at 45 degree water, a pH of 7.6, a normal summertime value leads to a CSI that is -.62, corrosive, while allowing it sit at 8.0 raises it up to -0.24, which is stated to be balanced.
So what do people that don't close their pool do during the winter? Do you let pH and TA take on higher values so that CSI doesn't get into the corrosive range? If you don't test for CSI, do you have different levels you aim for in the winter vs. the summer?
Let me be clear. I am not finding fault with other posts and other methodology. Those posters have far more knowledge and experience than I do. Maybe they close their pools and don't have to worry about this. I don't know. I'm just stating that for _me_, the CSI value has been important to look at in helping to balance the pool and I am not sure how to continue to do that as the temperature drops without raising some params (like pH) to compensate for the temperature drop.
Looking for thoughts and advice.