Clownfish fin parasite?

nmom · May 1, 2026

Hi! I a have a couple of months old 90L AIO. Stocked with 2 clowns - one regular ocellaris and one saddleback. The ocellaris is the first fish in the tank and has seemed very unhappy since the start (it is now in the tank for good 3 weeks). And by unhappy I mean it was only swimming at the top of the tank, never upright, except during feeding. It was never gasping for air and ate normally so I just figured it was assimilating to the new tank.
For the last week since I have added the saddleback it is swimming more around the tank, following the bigger clown, and is swimming upright. They do stay mostly in the top front corner. I have noticed the ocellaris has some greyish bubbles on its left fin. At first it looked like it was a part of the fin pattern but now it looks like it could be spreading. It is eating normally since the start (only artemia, but now also pellets). No aggression between them whatsoever. I think it had these spots before the saddleback was introduced to the tank. White spots are bubbles.
Parameters are ok. My salinity was a bit low at 1.022, but I have slowly raised it to 1.025. With the saddleback i added also 6 snails and 2 hermits and all seem totally fine. I also have GSP doing fine and a candy cane that is a bit retracted.
Any help would be greatly appreciated!

vetteguy53081 · May 1, 2026

nmom said:
Hi! I a have a couple of months old 90L AIO. Stocked with 2 clowns - one regular ocellaris and one saddleback. The ocellaris is the first fish in the tank and has seemed very unhappy since the start (it is now in the tank for good 3 weeks). And by unhappy I mean it was only swimming at the top of the tank, never upright, except during feeding. It was never gasping for air and ate normally so I just figured it was assimilating to the new tank.
For the last week since I have added the saddleback it is swimming more around the tank, following the bigger clown, and is swimming upright. They do stay mostly in the top front corner. I have noticed the ocellaris has some greyish bubbles on its left fin. At first it looked like it was a part of the fin pattern but now it looks like it could be spreading. It is eating normally since the start (only artemia, but now also pellets). No aggression between them whatsoever. I think it had these spots before the saddleback was introduced to the tank. White spots are bubbles.
Parameters are ok. My salinity was a bit low at 1.022, but I have slowly raised it to 1.025. With the saddleback i added also 6 snails and 2 hermits and all seem totally fine. I also have GSP doing fine and a candy cane that is a bit retracted.
Any help would be greatly appreciated!

I believe I see secondary bacterial lesions
Need pics under bright white lights- no blue to confirm

vetteguy53081 · May 1, 2026

nmom said:
Hi! I a have a couple of months old 90L AIO. Stocked with 2 clowns - one regular ocellaris and one saddleback. The ocellaris is the first fish in the tank and has seemed very unhappy since the start (it is now in the tank for good 3 weeks). And by unhappy I mean it was only swimming at the top of the tank, never upright, except during feeding. It was never gasping for air and ate normally so I just figured it was assimilating to the new tank.
For the last week since I have added the saddleback it is swimming more around the tank, following the bigger clown, and is swimming upright. They do stay mostly in the top front corner. I have noticed the ocellaris has some greyish bubbles on its left fin. At first it looked like it was a part of the fin pattern but now it looks like it could be spreading. It is eating normally since the start (only artemia, but now also pellets). No aggression between them whatsoever. I think it had these spots before the saddleback was introduced to the tank. White spots are bubbles.
Parameters are ok. My salinity was a bit low at 1.022, but I have slowly raised it to 1.025. With the saddleback i added also 6 snails and 2 hermits and all seem totally fine. I also have GSP doing fine and a candy cane that is a bit retracted.
Any help would be greatly appreciated!

Seeing on a larger screen, this unfortunately is ich.
You will need to place fish in Quarantine tank and treat with Coppersafe or Copper Power at therapeutic level 2.25 for a FULL 30 days (do not interrupt this 30 day period) monitored with a Hanna Brand copper test kit- No API brand. Also monitor Ammonia levels while in quarantine with a reliable test kit and add aeration during treatment using an air stone. All other fish in with it should also be removed as they have also been exposed to the parasites and placed in quarantine tank.
The display tank will have to be kept fishless (FALLOW) for 6-8 weeks to assure the existing parasites go through their life cycle without a host fish and die off. Inverts and coral can remain in the display (not treatment) tank during fallow period.
A quarantine tank can be as simple as a tank from a second hand store, a Rubbermaid type tub or a starter kit from Walmart which most of the needed essentials.

MnFish1 · May 1, 2026

Agree with Vetteguy - Ich - and I would follow his instructions. I thought I saw spots on your original photo. What other fish are in the tank?

W31Olds · May 1, 2026

Nmom, I do not see Ich on your Clowns. I see a lot of particular matter in the water making diagnosis difficult. I do see a Bacterial issue on the front fin of the Ocellaris. In this case a Video would work better to make sure.

vetteguy53081 · May 1, 2026

W31Olds said:
Nmom, I do not see Ich on your Clowns. I see a lot of particular matter in the water making diagnosis difficult. I do see a Bacterial issue on the front fin of the Ocellaris. In this case a Video would work better to make sure.

Its ich - Lets give proper assessments

W31Olds · May 1, 2026

Vette, i'm not prepared to say this is Ich. Looking at IMG 2534, you can clearly see that there is particular matter in the Water or on the Glass all around this Clown. Evident in the other images also. That's why the OP should post a video.

hatfielj · May 1, 2026

You can’t diagnose ich with such poor quality pics. The pics are back lit. The white spots you’re seeing are particulates in the water being illuminated by the light from outside the tank (like dust in sun light).
My vote is this is not ich. Could be some bacterial stuff on the fin but again hard to see.

nmom · May 2, 2026

I am attaching a video. It is very hard to take the video as the fish is very active and still quite small at around 3-4 cm. It is swimming at the glass most of the time, I do not know if this is considered rubbing or not.
Thanks!

W31Olds · May 2, 2026

I do not see evidence of Ich in the Video. The small Ocellaris has a torn up front fin most likely from aggression and it looks like a Bacterial issue on the fin also. Other than that, they both look good to me. The Glass Surfing should subside but also be aware that they may start fighting once settled in. Odd swimming patterns is common with Clownfish. I also see a Trochus Snail in your Video. Your Tank looks very new so you may have trouble with the snails as they need something (Algae) to eat. I probably would not treat for the fin yet. It may heal on its own.
@Jay Hemdal

Jay Hemdal · May 2, 2026

nmom said:
I am attaching a video. It is very hard to take the video as the fish is very active and still quite small at around 3-4 cm. It is swimming at the glass most of the time, I do not know if this is considered rubbing or not.
Thanks!

I don't see clear signs of ich in the video, but the previous pictures seemed to show it. I could see that many of the spots in the previous pictures were air bubbles and floating detritus, but some looked like ich spots. Depending on the timing between the taking of the pictures and taking of the video, the ich *might* have dropped off as it does in early infections (and then it returns).

That fin looks pretty damaged, did the larger clown do that?

nmom · May 2, 2026

Thanks. I also think it is not ich as both fish do not have any spots on them. All the bubbles are from the skimmer - I just can't get it to work right so I am running it with the valve cap off, so basically only for aeriation. I have filter floss in the first and last chamber.
But I am not sure the fin is damadged as the bubbles/spots seem additive on the fin. Could it be something stress induced? The behaviour/swimming patter for the first two weeks was very weird. Angled swimming at the top corner near the glass. I did change the flow a bit when adding the saddleback I suppose that also helped.
I think the ocellaris is doing much better now that he's not alone. There is absolutely zero aggression betwen the clowns. And there are no other fish in the tank. Except if the fin was damadged at the LFS.

Don't worry, I am feeding the snails some algae wafers 2 times per week.

nmom · May 4, 2026

I took the clown out of the tank to get some better photos. Please, can you check what this could be. It still eats and swims normally.

@Jay Hemdal @W31Olds @vetteguy53081

nmom · May 4, 2026

And just a note - the fin is not damaged. The transparent part is totally intact.

vetteguy53081 · May 4, 2026

nmom said:
I took the clown out of the tank to get some better photos. Please, can you check what this could be. It still eats and swims normally.

@Jay Hemdal @W31Olds @vetteguy53081

Top down pics in a cup are the most difficult to make any assessments. Worse id often a pic of fish out of water, also stressful to them Fish appears clear but continue to observe and if eating and breathing normal discounts some issues.
Need pics and video with fish swimming normal in tank displaying side views

Jay Hemdal · May 4, 2026

nmom said:
And just a note - the fin is not damaged. The transparent part is totally intact.

If you can get closeup pics and video from the fish’s side while swimming would help.

This may be Lmphocystis, a mild, self-limiting viral disease. Usually, it looks light gray, but I have seen it be this color as well.

nmom · May 5, 2026

This is the best I could do. @Jay Hemdal
It does seem to be spreading. Looks like a bunch of small bubbles. Thanks!

Jay Hemdal · May 5, 2026

nmom said:
This is the best I could do. @Jay Hemdal
It does seem to be spreading. Looks like a bunch of small bubbles. Thanks!

Tough to see, but I slowed the video down and it does look like atypical Lymphocystis. The best thing to do is just leave it alone - the virus will go into remission after 4 to 6 weeks. In some rare cases, the disease also infects internal organs, but there is no treatment for fish viruses.

Just be sure the other clown doesn't begin picking on this one.