Um..I kind of disagree....
In the long run, yes it is nice to have low CH water for filling the pool. It means your CH will build up very slowly over time with evaporation and refill. That's a good thing in the long run.
Initially however, you have to fill your newly plastered pool with water. With a CH that low, the water can very easily become aggressive toward the plaster surface as it is curing and will actually leach calcium from the shell which is not something you want to do. Initially your water will have high pH, about 8.2. The water results you are showing are not aggressive towards plaster because the CSI is close to 0. BUT, if you adjust the pH down to 7.6 and leave everything else the same, the water becomes very aggressive towards plaster (CSI ~ -0.65 depending on water temp). So having low CH initially can be somewhat detrimental to a new plaster surface. How detrimental it will be and whether or not you'll even see it is not something I can answer.
I'd feel more comfortable if we brought in some of our plaster experts on this because you may want to treat the water prior to or during the fill. Or, it may not matter as the fill water will increase in CH from the plaster dissolving a little bit into the the initial fill. I'm just not sure what the right approach is here. I'll PM the plaster guys and get their opinions.
