AEFW or Black Bugs

[Mrcote1]

Hi Everyone, im rapidly losing SPS frags and these little blackish grey things are all over the frags. Ive lost 3 frags so far and 2 others are dying. I have 3 large acro colonis im terrified of losing. Are these AEFW or black bugs and any recommendations on ridding them?

 

[Mrcote1]

 

[Mrcote1]

 

[Sam7]

looks like it to me but im no expert...flat worms that is.

 

[maroun.c]

Both flatworms and bugs wont kill corals that fast to have a fully bleached frag all of a sudden you would see signs and loss wont be that fast. This would be just RTN. The grey things on the frags are just pods.

 

[Notorious Reef]

Sorry to see this my man.. Dealt with these fellas earlier this year, on the bright side they are eradicable. The down side they are destructive lil buggers as I was rapidly losing acros similar to you.

Here is what they are:


definitely similar to AEFW but slightly different it seems.

The thing that fixed mine was following most of Monti Mikes guide as he ran into the same issue (Pages 7-8) https://www.reef2reef.com/threads/red-sea-reefer-200xl-build.694679/page-7

My steps (your mileage may vary, no promises):
Every 7 days for 6-8 weeks
- 7 minutes melafix dip
- 7 minute coral rx and flatworm exit dip
- Quick swish around in saltwater before returning to tank
Nightly
- Flatworm stop dosed directly to tank

From March 2026:

Same acro I took a frag before it got completely decimated September 30th 2026:

Hopefully this was helpful. There was like no information or barely any out there I could find when I first came across these. Good luck!!

 

[Mrcote1]

Sorry to see this my man.. Dealt with these fellas earlier this year, on the bright side they are eradicable. The down side they are destructive lil buggers as I was rapidly losing acros similar to you.

Here is what they are:


definitely similar to AEFW but slightly different it seems.

The thing that fixed mine was following most of Monti Mikes guide as he ran into the same issue (Pages 7-8) https://www.reef2reef.com/threads/red-sea-reefer-200xl-build.694679/page-7

My steps (your mileage may vary, no promises):
Every 7 days for 6-8 weeks
- 7 minutes melafix dip
- 7 minute coral rx and flatworm exit dip
- Quick swish around in saltwater before returning to tank
Nightly
- Flatworm stop dosed directly to tank

From March 2026:

Same acro I took a frag before it got completely decimated September 30th 2026:

Hopefully this was helpful. There was like no information or barely any out there I could find when I first came across these. Good luck!!

Thanks I appreciate it! Yea I can't find any info on these things really but that video is exactly what I have.

Did you dip all corals or only the ones with bugs? My large colonies there is no way I could get them out without serious destruction. I have 2 colonies that are softball/football sized

 

[Notorious Reef]

Yeah same here, info was limited and still is it appears.

So for me I only had one that had encrusted which was my little one above and I had to frag it anyway since it was being mauled. All my others were frags on a rack at the time so I did dip all of mine even if they showed no sign of them just to be safe. I believe Monti Mike did the same in his thread. Since you got those larger colonies I’m unfortunately not too sure my man.

 

[slingfox]

You could look into treating the tank with milbemycine oxime (aka Interceptor) once a week for 4-6 weeks. It you can’t get it from a vet you can buy online from the various Australia-based vet clinics. Not cheap but will eradicate most SPS pests.

 

[Mrcote1]

 

[Mrcote1]

The above video is them sitting in melafix right now at about 2x strength. Seems to have knocked a lot of them off the corals but they are still all moving around after 6 minutes which is a longer than recommended dip time. There are also way more than i thought. Dozens came off the three frags i dipped

 

[Mrcote1]

Alright at about 5-10x dose after 2 minutes they all stopped moving. Ill be a little more scientific on the measurement in about 5 days when i dip again.

 

[billyocean]

Had them in '23 when really nobody knew what they were. KCl (potassium chloride) at 2 tablespoons per gallon of dip worked. Treated as though they were the regular aefw. They will basically "rtn" an acro overnight as they are voracious. The fenbendazole flakes may work as an in tank treatment as well. Obviously the dipping approach means all acro coral tissue will need to be dipped.

 

[PeteyTu]

Is it the one?

 

[Mrcote1]

Mine look a bit wider than what yours look like in the cup but your closeup photo looks like it

 

[PeteyTu]

Mine look a bit wider than what yours look like in the cup but your closeup photo looks like it

How can I get rid of it? To be honest, I’m feeling quite desperate—there’s no way I can remove the entire coral colony to soak and treat it.

 

[slingfox]

How can I get rid of it? To be honest, I’m feeling quite desperate—there’s no way I can remove the entire coral colony to soak and treat it.

The answer is already in the thread above: Milbemycin oxime aka Interceptor

 

[PeteyTu]

The answer is already in the thread above: Milbemycin oxime aka Interceptor

regarding this new type of black AEFW—not just "black bugs."

 

[Viking_Reefing]

The answer is already in the thread above: Milbemycin oxime aka Interceptor

Won’t work as these are flatworms.

I had them about 4 years ago. Decimated a bunch of large acro colonies basically overnight. They were also very resistant to dips. I left them in coralRX and some other ones for about 30 minutes and they were still kicking.

The way I managed to beat them was dipping the pieces I could get of the rock and also blowing if every corals multiple times a day with a turkey baster. I also introduced about 5-6 wrasses, springeri damsels and a bunch of camel shrimp. After 3-4 months of that I couldn’t find any more and they have yet to returned. That was fun in a 1000L tank!
I also diced flatworm stop but no idea if that did anything besides making my wallet a little lighter and spiking my iodine.

Something by that’s fairly often used here in Sweden is a in tank treatment of fenbendazole. It’s generally effective but has some risks downstream.

 

[PeteyTu]

Won’t work as these are flatworms.

I had them about 4 years ago. Decimated a bunch of large acro colonies basically overnight. They were also very resistant to dips. I left them in coralRX and some other ones for about 30 minutes and they were still kicking.

The way I managed to beat them was dipping the pieces I could get of the rock and also blowing if every corals multiple times a day with a turkey baster. I also introduced about 5-6 wrasses, springeri damsels and a bunch of camel shrimp. After 3-4 months of that I couldn’t find any more and they have yet to returned. That was fun in a 1000L tank!
I also diced flatworm stop but no idea if that did anything besides making my wallet a little lighter and spiking my iodine.

Something by that’s fairly often used here in Sweden is a in tank treatment of fenbendazole. It’s generally effective but has some risks downstream.

I am facing a similar situation. Unfortunately, the SPS colonies have firmly encrusted onto the main aquascaping structure in the tank, making it extremely difficult to remove them for a medicinal dip. My plan is to first address the red bug infestation, then apply a topical KCl solution spray after lowering the water level, while also introducing snails and peppermint shrimp into the tank.