I had a problem with aptaisias and I bought an army of peppermint shrimps, 6 in total. Within a couple of weeks there were visibly fewer ugly brown flowers around. I use Joe Juice for the big ones and the shrimpies take care of the rest. I don't see the shrimps all that much but they are doing a good job at keeping the problem under control.
Aiptaisia is just a pain in the butt! It is very prolific and is capable of packing a powerful sting to corals, fish etc. It can, and does, spread uncontrollably in the right conditions. It can even create many new anemones if it is scrubbed, torn, etc. as the smallest if pieces can settle and form a new anemone. Much like Calfo's BTA splitting practices.
Natural controls include peppermint shrimp (make sure they are true pepps - Lusmata wurdemani ), the banded butterfly (Chelmon rostratus), the Copper Banded Butterfly (Chaetodon lunula) and the Black Lipped Butterfly (Chaetodon kleinii). The shrimp are your best bet, as the butterfly fish tend to have problems in captivity and can get rather large. There is also an aiptasia munching nudibranch (sea slug) (Berghia Verrucicornis) that would work, but they too have their "problems" in captivity; to include pump intakes, overflows etc.
Your best bet is to keep peppermint shrimp and for the larger aiptasia that the shrimp don't eat, use Joe's Juice or your own paste mixed of kalk and RO/DI water.
They THRIVE in nutrient rich tanks. Overfeeding your charges will most certainly aid in thier spreading. Keep that in mind if you tend to "broadcast" feed a lot of foodstuffs.
Maybe two of your friends swear by it, Carmie. I was so impressed with the results of it I added it to my web site. Check it out here - Joe's Juice. It works great and quickly.
The rest of the advice given by others is correct. Get rid of them as they appear and you should be able to keep them under control.
__________________ Amphibious
Reaching my 70th BD, I realize that I cannot help but grow old. However, I refuse to grow up!!! My wife would tell you, "He may be 70 but, He's going on 17". Life is wonderful with a woman like that.
Unless you want a "species only" tank I had an aiptasia in a 2 1/2 gallon tank (QT tank) that was soooo much fun. It got HUGE... I hand fed it chunks of clam and such and watched it digest it. I kept him until I needed to QT another fish...at which point, he suffered the osmotic shock and turbulent ending of my toilet
Joes juice is great and have used it in the past. But, I have found the best way to get rid of them and to keep them gone is the good old peppermint shrimp. I have two of them in my 90gal and I have no more aipstasia in my display but a few in the sump were the shrimp can't get to. I could never keep them in control with Joes juice, but it does work better than other brands ***** that I have tried.
Also my shrimp are a breeding pair, their spawn helps me feed my coral and fish once a month.
I note where it is connected to, pull the rock and let it sit for about a minute for most of the water to drip off, and then turn the rock over so the the Aptasia area faces down, and light my BIC directly on it for about 20 seconds.
I note where it is connected to, pull the rock and let it sit for about a minute for most of the water to drip off, and then turn the rock over so the the Aptasia area faces down, and light my BIC directly on it for about 20 seconds.
Toasted!!!
That works fine when you can remove the rock. When you can't, Joe's Juice to the rescue. I sell a ton of it because it works without harm to other things like coral. I've inadvertantly got it on corals and had no problems.
Reaching my 70th BD, I realize that I cannot help but grow old. However, I refuse to grow up!!! My wife would tell you, "He may be 70 but, He's going on 17". Life is wonderful with a woman like that.
WOW! Yall are pretty adamant about Joe’s juice! Never tried it I use peppermint shrimp also but I’ve had a couple that were too big for the shrimp to mess with. I’ve just taken boiling water out of the microwave and using a turkey baster shot them with
icon under their name to add to their reputation. 
USA 
I was so impressed with the results of it I added it to my web site. Check it out here - 
I had an 
