I can speak from experience on the high alkalinity fill water. My well water is over 400 TA. I hauled in 15,000 gallons initially, but it was from a town well and had a TA of 280. The best advice I can give is that rainwater is your friend. Go for a mesh winter cover so you collect all of the rain over the off-season. Follow the advice about maintaining a low pH and aerating. I was able to get mine into a reasonable range (180 when I closed last fall) without much stress.