The only success was when I would pull a rock and place it in a separate bucket, let it sit for a day or so and then remove all of the bristleworms/amphipods I can find then add three or four Berghia. When the rock is almost clean, return the rock to the display with the Berghia embedded in it somewhere, That rock stays pretty much clean for several weeks.
I don't know if the Wrasses are getting them or the Aiptasia are getting them or both. Plus while you don't see the bristleworms and amphipods without searching, they are there probably eating most if not all of the eggs.
The tank may actually be beyond what Berghia can fix. I can truthfully say I have never seen a tank as overrun with Aiptasia as my tank is right now. one insight came when I was watching our Berghia tank one day. We had a lot of Aiptasia in the tank as we had just reseeded it. There was one large Berghia on the opposite side of the tank from the others and the light was on so it wanted to hide. It tried to cross the tank but could not because it kept getting stung. Since then we are careful to not add too many Aiptasia to the Berghia tank at once. There are very few places in the display that are not completely covered by Aiptasia.
I think I need a multi-front campaign to start to win the Battle of the Lagoon:
- Pull non-coraled rocks and let Peppermints have at it (this is to be as little as possible as it disrupts the fish pecking order for days at a time)
- When done, remove rock from Peppermint Parlor, infuse with Berghia and return to tank
- I've added a Kleini Butterflyfish that is pecking at the Aiptasia but not really with enough gusto so
- May need to add Aiptasia-eating Filefish as well
- I just got a fresh batch of F-Aiptasia, go after the biggest ones manually
- Continue to harvest 50 or so Aiptasia per day for the Aiptasia farm from the sand
If that doesn't work or at least show continued progress, buy new tank, transfer fish and buy new rock, move existing tank to back yard, buy flamethrower, have a BBQ.