What is wrong with my fish?

[KLtropical]

Any suggestions as to what has happened to this little fella? I noticed it yesterday.

The tank was set up 10 months ago and is approx. 500 l. / 135 g. It contains a range of Southeast Asian species:

Kuhli, Clown, Vietnamese Hill, and Borneo Loaches
Siamese Algae Eaters
Boesemani and Neon Rainbow Fish
Harlequin and Scissortail Rasbora

I lost a Scissortail and a Hill Loach in the past week or so. This is not a common occurence, and I did not notice any spots on them.

These are the tank values from a water change earlier in the week. The tap water contains chlorine, so I add a neutralising agent:

2025.01.01 (30% water change)
pH = 6.8
Ammonia = 0
Nitrite = 0
Nitrate = 40

 

[GaryE]

That could be as simple as an infected wound. Or a bacterial infection may be brewing.

We all have different approaches, but you have a lot of fish in that tank. It's going to get worse as the clown loaches outgrow the aquarium. Tanks that crowded put us on treadmills as far as water changes go, and as the fish grow, you can expect disease to start thinning the herd. Even 50% weekly water changes are not going to be able to cope longterm. So you may be seeing the start of that - losses without an epidemic.

It's a beatiful tank though. You put a lot of work into it to keep it that nice. It's quite a task with that bioload.

 

[lottabubbles]

long ago I had a beta that got stuck on the filter intake and it sucked all the coloring off the area. the poor beta died in the process because it's fins were wrapped around it too.

 

[KLtropical]

That could be as simple as an infected wound. Or a bacterial infection may be brewing.

We all have different approaches, but you have a lot of fish in that tank. It's going to get worse as the clown loaches outgrow the aquarium. Tanks that crowded put us on treadmills as far as water changes go, and as the fish grow, you can expect disease to start thinning the herd. Even 50% weekly water changes are not going to be able to cope longterm. So you may be seeing the start of that - losses without an epidemic.

It's a beatiful tank though. You put a lot of work into it to keep it that nice. It's quite a task with that bioload.

Thank you for the feedback. I will wait and see how it develops. Hopefully it will resolve itself over the coming days.

I am not too concerned about the bioload (yet), but am starting to consider if I can return the clown loaches back to the seller or elsewhere. They are fun to watch, but also creating quite a mess in the tank while digging away at the gravel and pushing plants and rocks around. It seems they can be stressful for the other inhabitants.

Overall, there doesn't seem to be much bullying going on, except one of the Siamese Algae Eaters chasing the other every now and then.