Thanks for your note Janet. I have not had the water tested for metals. Took a sample to a pool store and they did a test strip--that wasn't any help, was it? Next day, took another sample to another store and they attempted to test but said chlorine was too high and couldn't test. Also no help. Thank goodness for this forum. We do have well water but haven't filled for several days. The color is more cloudy green--I don't think I have anything growing in there. The liner in not slimy and nothing is falling on steps to indicate algae. I can purchase a sequesterant but shouldn't I get the balance right before I try to manage another issue?