Not really sure having never dealth with them. You may only make them worse if they're irritated. I'd go with the more proven approach sugested earlier before trying anything unproven. My experiments on the nuisance coral are promising but may yet be unsuccesful. I'll be really bummed out if the Xenia only grows more I tried it on the smallest little rogue patch. Like two tiny waving hands.Would that laser take out digitate hydroids you think?