Clean algae from zoa frag

[lastlight]

Seems a person needs to wait a long time in this hobby to know anything for certain. The exact same algae that I was trying to eradicate on 3 separate frags has returned on all of them. I'm not sure if I should continue dipping or increase the concentration. The zoas fully open within hours/a day as it is. This is an insanely intrusive algae that threads between polyps and chokes the colony. It spread from frag 1 to frag 2... a single tendril of the stuff that snaked to a neighboring zoa colony. It will even fuse nearby sand and try to choke it!

Thinking perhaps I should just play it safe and get rid of them...