OK, I *think* I've got the algae under control (water is blue, overnight FC drop test was 0.5 ppm) but my water has a slightly white cloudiness to it instead of being clear.
Test results last night:
I added the little Calcium Chloride I had left in the shed and that raised my CH to 120. Reading the book that came with my Taylor test kit, I see "Low calcium hardness: corrosive water - etching of plaster, pitting of concrete, dissolving of grout". We *do* have fairly soft water here, which is good for a lot of things but I guess not good for maintaining CH.
Our pool is, according to the inspector/pool service guy who maintained it for the previous owner, a concrete/plaster one that for reasons unknown was re-lined with fiberglass by the previous owner. The fiberglass has been chipped in spots so there's some exposed concrete/plaster, and the grout *has* been pitted over the past few to several years (someday we *will* have enough $ set aside to have it resurfaced, sigh....).
I'll be heading out to the pool store for more Calcium Chloride later this morning, but just curious as to whether the white haze sounds like just dead algae or if it's dissolved pool surface. Thanks!