Same with me...initially they seemed to be gone but eventually returned. I now have them in two placed. On one I used pickling lime and put a layer over them. That seems to have worked but unfortunately I didn't cover them all. This weekend I'm going to try some aptasia x and see if that does anything.Going back down this rabbit hole.
Dosed last fall and followed directions to a 't'. It appeared to kill the BCP with nominal effect on everything else. 8 months later they're back and in force.
Treated ~340gal of water with 500mg. So far so good. If this plays out like the first time I'd like to dose again in 4-6 weeks and deliver the coup de grace. Has anyone tried a proactive second round of dosing previously?