Here's my story:
Early this swim season I switched our pool over to the BBB method and have been getting excellent results.
We went on a short vacation of 7 days and while away I put some pucks in the skimmer to help keep up. On returning I adjusted the balance to normal levels and saw that I was getting small patches of green algae showing up in the less circulated portions of the pool. I brushed and cleaned it thoroughly and did an overnight FC drop test with the following numbers:
In the morning I retested and found that the FC had dropped only .5 which in my experience does not indicate a need to shock. The water looks perfectly clear.
It had been quite some time since I tested the CYA and after realizing that it was 50 I raised the FC from my usual 5 to 8. The algae does not seem to be returning, the water is clear and the CC remains at 0.
Here's my question:
I tested the following morning and found that my FC was down 4 PPM.
Is this normal?