It's now been about 3 months since I used fenbendazole (220 mg for 150 total gallons) to rid my tank of a huge infestation of BCP and also some GSP. (my rock was probably 95% covered with BCP). I treated the tank for 3 days (with no skimming or filtration) and then did a 20 % water change and restarted skimming and filtration (carbon and GFO). About a week later I did another 20% water change. I got total die off of the BCP and GSP. Lost a gorgonian and perhaps half of the hermit crab and snail population. All coral (SPS and LPS) and fish did well. Didn't hurt the aiptasia either. Due to the massive die off my waste levels surged and that was followed by a surge in algal growth everywhere. After a month of filtration, I used a turkey baster to blow off the dead matter and algal off the rocks, glass, and sediment. Suctioned up most of the dead matter. Did that again a few weeks later. Tank looks great now, but it takes patience for things to return back to normal. Would I use the dewormer again? Yes, without a doubt.