Had an "unscheduled" rain event last evening, just before my usual testing time. I say unscheduled, because the storm moved in sooner and faster than predicted.
I've been running my FC level where it seems to be most stable, between 4.5 and 5.5. CYA is at ~35 (1/3 below the 30 mark).
Did my testing this morning, and contrary to what had become the norm, pH didn't move, but FC went what I would consider way down. This morning's test showed 2.5 first test, and 3.0 on verification test. 0 CC on both tests.
Added bleach, will retest later.
Rain added about 1" of water to the pool. I've never had that much of a drop in FC due to rain. Usually the pH jumps from 7.4 to 7.8 or better. May have been something odd about what the rain washed off the trees? There is a large amount of dust that has piled up on the bottom now, slightly more than normal.
I'll be monitoring the water closely today, and be prepared to raise to shock level if needed
Just thought I'd try to get a little input from more experienced folks here.