I started using the TFP methodology last year and am comfortable using the TF-100 test kit. We are 'lucky' enough to have the special bacteria that consumes CYA over the winter, which was a blessing/nightmare last year when the process resulted in extremely high ammonia readings. We got thru that and kept the CYA at around 40 last year, resulting in a much lower ammonia reading of 0.5 - 1.0 ppm ammonia when we opened the pool this year and <20 ppm CYA. The ammonia level disappeared to 0 quickly. The pool cleared in 18 hours and has been sparkling ever since. We managed to get the CYA up to about 25, and we have been SLAMing for 10 days. I've kept the FC at 12-15 and got the CYA up to 25. However, I haven't been able to get the CC down lower that 1 (2 drops using TFP-100 test kit), so we keep SLAMing. We've added stabilizer in low doses over a few days, and tested the CYA this morning and it is back below 20 ppm and the CC has increased to 1.5 - 2.0. I'm concerned that the CYA eating bacteria is still present even after high FC levels for 10 days and that by adding more stabilizer we are feeding the CC. If so, we have a vicious cycle. Any thoughts/advice?
Other metrics: TA is 90 and pH was 72-75 before SLAM. Pool is in sun 12 hrs a day and water temperature is now 78 degrees. Less than an inch of rain since opening pool. The only other possible issue is a relatively high phosphate reading of 880, but I've read that this can be controlled with good chlorine levels.
Thanks for any help.