Hey Megan !!!
Consider this about your phosphates. I am normally hardcore in the 'they don't matter' category. I'm usually one of the first ones singing to keep your FC up and they don't matter. Especially not the way the pool store vilifies 250 parts per *billion*.
But at some point, and it's a different POV for all of us (2k/3k/4k), you are all but begging the universe for a power failure during a local bleach shortage. Things happen even when we stay on top of the chemistry like hawks. Or a family emergency puts poolcare on the back burner. And if FC was to drop because of it, you'd have a runaway algae train with a high number of phosphates. Again. I'm talking actually high and in the multiple thousands. I wouldn't even think about it until 2k, but I'd be addressing it by 4k.