No, it doesn't kill much of anything IME. I ordered a monti rock from a vendor knowing it was wild and likely would have monti nudi's and used a strong dip. In short it stuns most inverts including the SPS but doesn't actually kill it, you still need to blast it with a powerhead or toothbrush. I only did one treatment in my tank and I will never use it again, my skimmer wouldn't work correctly for 4 or 5 days afterwards and the planaria are still there. It says to use it for 7 days I believe but I never made it that far, I love it for my FW tank.