Clownfish Not Eating, Struggling to Swim, and White Poop – What Should I Do?

[Wageningen]

On Saturday, I purchased two clownfish. One of them seems fine and is eating the frozen food I provide, but the other one is showing some concerning signs:

• Not eating (ignores pellets, frozen brine shrimp, and frozen Artemia)
• Struggling to swim (seems weak and unsteady)
• Passing white, filamentous poop

This makes me suspect an illness, but I’m unsure what it could be or how to treat it. My tank parameters are:

• Temperature: 25°C
• Salinity: 1.025 - 1.026
• NO₂: Near zero
• Nitrate: 3-5 ppm

Does this sound like an internal parasite or infection? Should I try a different food, or is there a treatment I should consider?

I also attached pictures of the tank and of the other new gusts. I started the cycling on the 1st of december 2024 and used live sand, bacteria and later on I added also few artificial live rocks

Any advice would be greatly appreciated!

Thanks in advance!

 

[Jay Hemdal]

On Saturday, I purchased two clownfish. One of them seems fine and is eating the frozen food I provide, but the other one is showing some concerning signs:

• Not eating (ignores pellets, frozen brine shrimp, and frozen Artemia)
• Struggling to swim (seems weak and unsteady)
• Passing white, filamentous poop

This makes me suspect an illness, but I’m unsure what it could be or how to treat it. My tank parameters are:

• Temperature: 25°C
• Salinity: 1.025 - 1.026
• NO₂: Near zero
• Nitrate: 3-5 ppm

Does this sound like an internal parasite or infection? Should I try a different food, or is there a treatment I should consider?

I also attached pictures of the tank and of the other new gusts. I started the cycling on the 1st of december 2024 and used live sand, bacteria and later on I added also few artificial live rocks

Any advice would be greatly appreciated!

Thanks in advance!

I see that a lot in clownfish here - there can be multiple causes. Sometimes it's stress from being beaten by another clown (don't think that applies here). In other cases, it is from an overgrowth of normal gut protozoans. Trouble is, medicated food is how you need to treat that, and if the fish isn't eating, that's not an option. I'm also not convinced that there isn't some clownfish virus out there...of course, those can't be treated either.

You could try Ruby Reef Rally Pro, at least that won't hurt your corals.....

 

[vetteguy53081]

On Saturday, I purchased two clownfish. One of them seems fine and is eating the frozen food I provide, but the other one is showing some concerning signs:

• Not eating (ignores pellets, frozen brine shrimp, and frozen Artemia)
• Struggling to swim (seems weak and unsteady)
• Passing white, filamentous poop

This makes me suspect an illness, but I’m unsure what it could be or how to treat it. My tank parameters are:

• Temperature: 25°C
• Salinity: 1.025 - 1.026
• NO₂: Near zero
• Nitrate: 3-5 ppm

Does this sound like an internal parasite or infection? Should I try a different food, or is there a treatment I should consider?

I also attached pictures of the tank and of the other new gusts. I started the cycling on the 1st of december 2024 and used live sand, bacteria and later on I added also few artificial live rocks

Any advice would be greatly appreciated!

Thanks in advance!

If fish not eating, check with store you got them from to see what they were feeding them. I suspect brine shrimp, mysis shrimp or both. I know live brine is getting less common at LFS but if you can find some - May work
How did you acclimate fish and for how long?
Fish were not quarantined which is recommended but at this point, tank looks awfully new. Was it cycled and how long running?
How are you testing water?

 

[Wageningen]

Here are the details:

• Feeding: At the store, they were fed frozen food (mysis and artemia). I bought the same food, but the sick fish ignores it.
• Acclimation:I followed the store’s advice:
  • Floated the bag in the tank for 10 minutes to equalize temperature.
  • Transferred the fish to a bucket with half tank water and half bag water.
  • Waited 10 minutes, then moved them to the display tank (DT) using a clean hand.
• Quarantine: I didn’t quarantine them myself, but the store (coralandfishstore.nl) does quarantine their fish. These are captive-bred from De Jong Marine Life (Netherlands).
• Tank Setup & Cycle:
  • Started cycling on December 1, 2024, using live sand and a dead shrimp (removed after a few days).
  • In January, I added 1kg of artificial live rock and dosed cycling bacteria, just to be sure.
  • Did multiple water changes before adding fish and introduced a few snails in early January already (I later learned that CUC should usually be added a bit later, but i wanted to be sure that my DT was "livable").
• Testing & Equipment:
  • I use Salifert test kits for NH3, NO2, NO3, and PO4 and a refractometer for salinity.
• Medication Availability: I looked for Ruby Reef Rally Pro, but it’s not available anywhere in the Netherlands.

 

[Wageningen]

The fish is still not eating and keep making the white filament poop....
I feed twice a day and I try 3 different types of frozen food (artemia, mysis, and a mix with brine)
Very rarely the fish show interest for the food, and even more rarely takes a small bite and then spit it. The other one eat voraciously. The nh3 betwen 0.15 and 0.25 with the salifert test ,no2,no3 are still zero or very close. temperature 25 celsius

 

[Wageningen]

Do you think Selcon or Garlic can be of any help?

Is there a product on this website that might be worth a try? https://coralandfishstore.nl/nl/wat...0NzAwOC4xLjEuMTc0MDE0NzAyMS4wLjAuMjQyNzI5Mzg0

 

[Jay Hemdal]

Do you think Selcon or Garlic can be of any help?

Is there a product on this website that might be worth a try? https://coralandfishstore.nl/nl/wat...0NzAwOC4xLjEuMTc0MDE0NzAyMS4wLjAuMjQyNzI5Mzg0

Selcon and garlic won't cure a fish of any disease, and won't really help as dietary aids in a fish that isn't eating.

Sorry - I'm not familiar with medications from Europe. Even if you had access to drugs from the US, I wouldn't have a good recommendation for you because some causes of this have no treatment. You could try dosing a hospital tank with metronidazole, but you cannot treat your main tank, as it can harm the corals.

 

[Wageningen]

thank you
- I would use Garlic to try to increase the appetite of the fish - is that snake oil or it make sense?
- sorry if insist, I found this product, what do you think: https://coralandfishstore.nl/nl/wat...0NzAwOC4xLjEuMTc0MDE0NzA3MS4wLjAuMjQyNzI5Mzg0

 

[Jay Hemdal]

thank you
- I would use Garlic to try to increase the appetite of the fish - is that snake oil or it make sense?
- sorry if insist, I found this product, what do you think: https://coralandfishstore.nl/nl/wat...0NzAwOC4xLjEuMTc0MDE0NzA3MS4wLjAuMjQyNzI5Mzg0

No, garlic won’t start a fish feeding again if it has stopped. It is a mild stimulant at best, and some people find it has the opposite effect.

 

[Wageningen]

ok I managed to get my hands on metronidazole for human use.
I disolved 25mg/l and I put the fish in a 30 l quarantine tank.
In the quarantine tank there is a live rock from the original tank, a thermostaat a pump for the movement, nothing else.

Can you guide me on what to do in the coming days?
Shall I change the water everyday? All of it or partially?
How long should the treatment last?

 

[Wageningen]

ok I managed to get my hands on metronidazole for human use.
I disolved 25mg/l and I put the fish in a 30 l quarantine tank.
In the quarantine tank there is a live rock from the original tank, a thermostaat a pump for the movement, nothing else.

Can you guide me on what to do in the coming days?
Shall I change the water everyday? All of it or partially?
How long should the treatment last?

when to add more metronidazole?

 

[Wageningen]

should I put also the healthy clown fish with him?

 

[Jay Hemdal]

should I put also the healthy clown fish with him?

If the healthy clown is showing NO symptoms, I would leave it where it’s at.
Metro is dosed 25 mg/l every other day for three treatments. Water change prior to the second and third treatment won’t hurt.
With human metro pills, you need to know if there is any binder or filler in the pills. You need to dose for the actual active amount of metro.

 

[Wageningen]

Thank you.
If the treatment doesn't work, should I expect the fish to start eating in a matter of days?
If the treatment doesn't work: shall I try with praziquantel?

About the second treatment:
the tank is 30 liter. I will change 15 liters tomorrow.
After I change the water shall I dissolve 30*25 = 750 mg or 15 * 25 = 325 mg in the tank?
(What I mean is: does the concentration of antibiotic decrease for some sort of chemical brakdown or stay stable?)

 

[Wageningen]

Thank you.
If the treatment doesn't work, should I expect the fish to start eating in a matter of days?
If the treatment doesn't work: shall I try with praziquantel?

About the second treatment:
the tank is 30 liter. I will change 15 liters tomorrow.
After I change the water shall I dissolve 30*25 = 750 mg or 15 * 25 = 325 mg in the tank?
(What I mean is: does the concentration of antibiotic decrease for some sort of chemical brakdown or stay stable?)

Sorry, I made a typo, I meant "If the treatment does work, should I expect the fish to start eating in a matter of days?"

 

[Wageningen]

please help: I don' understand if i have to ADD 25mg/l every other day or to simply KEEP the concentration after water changes