How do I get rid of Aiptasia and why is it bad? By Lev Ingman
The most important thing you need to do if you start getting an Aiptasia problem is to ACT EARLY!! If you do not act early and get on top of it then it can take over the tank and kill livestock. DO NOT attempt to tear the Aiptasia out, do not poke at it, pick at it, or attempt to kill it in any non-conventional fashion because it will break apart and begin to grow everywhere. The best thing to do is to get a product that is designed to kill Aiptasia like AiptasiaX. Most of these products are made of a concentrated dose of calcium that needs to be injected into the middle of the aiptasia. Be careful not to use too much because it will raise the calcium level in your tank. Do not get any into your anemones because it may kill them as well. In addition to using the Aiptasia killing product, get some peppermint shrimp that will sometimes eat the dying Aiptasia and the small Aiptasia that you did not get to. Jump on it early or you will regret it. You can also mix some Kalkwasser concentrate with water(into a paste like consistency) and try injecting that into the Aiptasia(This is more dangerous because its hard to get the correct consistency and you can overdose your tank with Kalk!) but be very careful because this may mess with your PH and Calcium levels and can overdose / shock your tank.
You now also buy Berghia Nudibranches online and slowly introduce them into your tank(Drip acclimate!) and they will usually do a great job of eating all the Aiptasia the natural way.