I've experienced monti caps accumulating stubborn little tufts of hair algae from time to time. One colony (a strawberry fields beauty) that was looking great except for that fact started a skirt of hair algae around the rim. I could not permanently remove it by tooth brush no matter what I did. I chose to employ the "Justin method" (our last meeting's speaker) and do a 3% Hydrogen Peroxide dip. I removed the cap from the tank and rotated it's rim in a straight solution of 3%. I gave it about a minute of contact and returned it to the tank. bubbles and slime formed immediately where the solution made contact and I held my breath. 20 minutes after reintroduction to the tank, I blew off the bubbles and slime with my trusty turkey baster and "Voila" extended polyps and happy tissue. after two more days, the algae is gone. I tried the same technique with a frag of zoas that had become covered with algae and the same results: Two days later, no algae and healthy zoas.
Take away message: In case you've considered doing this, I've had good results
Take away message: In case you've considered doing this, I've had good results