How to get rid of aiptasia (what we tried, what we skipped, and what worked)
What worked for us was berghia, tiny sea slugs that eat aiptasia and nothing else. We put four in our 16 gallon with about six aiptasia, and the aiptasia were gone in about a week. Pulling, scraping and cutting aiptasia can actually make more of it, and the chemical and animal options all came with trade-offs we didn't want.
Why aiptasia is so hard to get rid of
Aiptasia is a small pest anemone that hitchhikes into reef tanks on rock and coral. It looks harmless at first, and then one turns into five. The hard part is that almost any piece left behind can grow back.
We know this better than most people, because we've spent months trying to make aiptasia grow on purpose. We raise it to feed our berghia. Everything that makes aiptasia a nightmare in a display tank is exactly what we were trying to make happen.
Pulling, scraping and cutting: why we'd skip them
When we were trying to grow more aiptasia, we tried everything people said would work. We rubbed the rock with a toothbrush, scraped, pulled, and clipped just the tentacles.
What finally worked was clipping the whole head off. The stalk grows a new head, and the clipped head reattaches somewhere new. Two aiptasia for the price of one! Great news for our aiptasia farm. Not so great if that's your display tank and you're trying to get rid of it.
Clipping the head off: the stalk grows a new one and the head reattaches (starts at 2:23)
If you've been cutting or picking at your aiptasia and it seems to be multiplying, that might be why.
Aiptasia-X and other chemicals
We actually bought Aiptasia-X. Then we read how to apply it without hurting the zoas growing right next to our aiptasia, and it seemed so complicated that we never used it. We weren't willing to risk corals we love on getting it exactly right.
Peppermint shrimp, butterflyfish and filefish
We haven't used any of these for aiptasia ourselves. What we have done is read a lot of Reddit threads and reef forums, and we've seen the same stories over and over:
- Peppermint shrimp picking at corals, or getting used to the food you feed your fish and losing interest in the aiptasia.
- Butterflyfish being really hard to keep, with so many of them not surviving, and some picking at coral too.
- Filefish that never touch the aiptasia, nip at zoas and soft corals instead, or switch to fish food once they figure out it's easier.
Plenty of people have had good luck with these, and we're not saying they never work. These were just enough stories that we didn't want to roll the dice.
What worked for us: berghia
Berghia are tiny sea slugs (nudibranchs) that eat aiptasia and nothing else. They don't bother coral. They don't bother your fish or your cleanup crew. And they can't get distracted by the food you're feeding everyone else, because they don't eat it. They just keep eating aiptasia until it's gone.
In our 16 gallon, we had about six aiptasia and added four berghia. We saw them the first night and then never saw them again (which is normal, and we wrote a whole post about it: I added berghia and now I can't find them). The aiptasia were gone in about a week, and we haven't seen one in that tank since. That tank has two clownfish, a firefish, a goby, pistol shrimp, and a lot of hermit crabs and snails, and none of them got in the way.
One small berghia taking on an aiptasia about four times its size
The one trade-off is that once the aiptasia are gone, berghia have nothing left to eat. It's one of the things we're learning more about now that we're breeding them.
If you just found aiptasia in your tank
- Try not to pull, scrape or cut it while you decide what to do. You might end up with more.
- Count how many you can see and where they are. It helps you figure out how many berghia you'll need, and our berghia calculator can give you a starting number.