Been hanging around a while, I suppose I should say hi... my dad built a concrete pool when I was a kid, I helped take care of it. We first had a filter with some kind of cylindrical cartridges, after a couple years that failed and we got a sand filter. The drop tests for chlorine and pH haven't changed any since then! But pool chemistry seems to have advanced considerably since then. I'm certain my dad would have been on top of everything that was known in the 1960s-70s, he was a chemical engineer.
So, we bought this house about 6 months ago and it came with a pool. And a hot tub. My wife is amused, but still pleased, at how I've taken to the care and feeding of the beasts. Finding this forum has been a godsend.