Recent convert to the BBB method. Testing with TF-100, and my numbers are in line with the recommended values for CC, CYA, pH, TA. 18000 gallon, in ground, gunnite pool. Was using trichlor until I noticed brown stains and found my CYA= 100+.
pH= 7.2 (lowered with MA since I am going to work on the stains which could be iron vs Ca scaling)
So here is my issue- shocked with 6%chlorine up to 13 based on the Cl/CYA chart. Next morning FC fell to 12. At the end of that day the FC had fallen to 7 - sunny day here in Houston, 3 people swam for 1 hr. The following morning the FC was 6. No swimming that day (Memorial Day), now at night the FC is 0.5-1. Added 6% bleach with a target of 10 (to give me some leeway for tomorrow).
I don't think I have any organics/algae since I passed the OCLT. Water is very clear. I thought the daily drop in FC was supposed to be 2-3 not 5-6. Just want to make sure that I'm not missing something.