Thought I'd share the following. It was written for another use, but thought is might help here.
The following summary of aiptasia control options are based upon 5 years of conversations with hundreds of people and our own experiences. It’s no secret that there are not many hard and fast rules in this hobby. The following is a general review of these options. Each hobbyist experiences may vary. Use this information as you consider what method is best for your aiptasia problem.
Berghia Nudibranchs
Strengths: Berghia eat only aiptasia anemones, nothing else. They can crawl all over your tank to eat the aiptasia you see and the ones you do not see. If acclimated and added to a well maintained tank, they are hardy invertebrates. They may reproduce to help speed up aiptasia eradication.
Weaknesses: It may take time for the berghia to solve heavy aiptasia infestations especially if you do not get the correct number of berghia for your situation. If the berghia are not at least ½â€Â, they should be maintained in a small tank or a container of at least 1 gallon of water until they grow larger before they are placed in a display tank.
Predators: Peppermint shrimp, nocturnal scavenging fish including coris wrasses that hunt at night; to a lesser extent, underfed large brittle or serpent stars, emerald crabs and coral banded shrimp.
Peppermint Shrimp
Strengths: When they work, they work fairly well. They typically eat aiptasia fairly quickly.
Weaknesses: Some stores do not know what type of peppermint shrimp they are selling. So the shrimp you get may or may not be the kind that will eat aiptasia. Peppermints would rather eat fish food. They can be destructive to corals, desirable anemones and clams. Smaller peppermints may not acclimate well. Some will eat only small aiptasia (disk smaller than a nickel).
Predators: Fish which eat ornamental invertebrates such as hawkfish, various dottybacks, various wrasses, some puffers, some triggers, eels, ect.
Copperbanded Butterflyfish
Strengths: When they eat aiptasia, they are usually fairly quick about it.
Weaknesses: Difficult fish to acclimate to a home tank. It may take several fish to find one that will live. When they live, they are hit or miss on eating aiptasia. Some are easily bullied by other fish and it can be difficult to get them to eat foods added to the tank. Some may nip at corals and clams. Not an appropriate fish for tanks under 50 gallons.
Racoon Butterflyfish
Strengths: The most dependable aiptasia eater of the butterflyfishes. About 95% of them will eat both aiptasia and majanos anemones. They usually clean a tank out of aiptasia quickly.
Weaknesses: They will likely eat many types of soft and LPS corals, clams and desirable anemones. Not an appropriate fish for tanks under 50 gallons.
Injected Chemicals and Potions
(includes Kalkwasser preparations such as homemade mixes and store bought preparations; lemon juice; boiling water, ect.)
Strengths: Inexpensive and fairly easy.
Weaknesses: Risky since this technique might make the aiptasia problem worse by spreading small pieces of the dying aiptasia around the tank. Those pieces grow into a lot of small aiptasia. May cause injury if you accidentally apply to corals. Can only apply them to the aiptasia you can reach. Can alter tank pH when used in large doses.
Manual Pulling and Scraping
Strengths: Free and fairly easy.
Weaknesses: This is a waste of time. Pulling and scraping may make the aiptasia problem much worse by spreading small pieces of the aiptasia around the tank. Those pieces grow into a lot of small aiptasia. It may be hard to get at all of the aiptasia using this method.
Soaking Rock in Fresh Water
Strengths: Free
Weakness: Don’t bother. It will kill all life on the rock except the aiptasia. Aiptasia can live through fresh water soaking.
A couple of other notes…
If you try kalk paste or other injection methods, there is a risk that it will make many small aiptasia out of the one that you killed. We talk to people almost every day who report the aiptasia spreading after using these chemical methods. If you try them, your best bet is to turn off all powerheads and siphon off the dying aiptasia after you apply the chemical.
To help slow the spread of aiptasia, cut back on how often and how much you are feeding your tank. One of the reasons aiptasia thrive is that we feed them while feeding our fish. Assuming you have no anthias or other fish which need to eat everyday, cut back your feeding to a few times a week. Many fish do not need to eat everyday. Feed in small doses, and let the fish eat all food before adding more to avoid uneaten food from feeding aiptasia.