I am by no means an expert, but I have been testing CBA in 16oz apoth with 2 x HTP93 and it's going well thus far. I had tested with 2 x HTP73 and was barely enough to get through the bottom 1/2. Maybe the dye/FO combo....or too much FO?? I am sure someone with more knowledge will weigh in here soon. Goodluck! Kim