My tap water clocks in at 8.3-8.7 ph and around 350 ppm. I don’t have any analysis handy, but judging by what I’ve seen come out of neighborhood houses without water softeners, it has loads of calcium.
I tote two 4.5 gallon cat litter buckets full from the outside spigot (which doesn’t pass through the water softener) and aerate it for 24 hours. Then stir in a teaspoon of citric acid powder for each bucket. Drops ph to 6.3-6.5 range.
I run SIPs with organic soil, so far no water issues. When I first started growing I was using water from the dehumidifier. Low ppm and I supplemented with cal-mag. Adjusted ph after mixing nutes. And had problem after problem. Much respect for the folks that can produce primo bud with that, but that just ain’t my area of expertise. Lol