Vla79

That's really interesting, I hadn't seen that before. Thanks for the link! Thanks for checking in. I lost three more within a couple days of the last post, but it's been several days since the last death and everyone looks decent. I've been doing 25% water changes every 2-3 days with no salt and no meds and trying to keep stress low. Fingers crossed that the worst is over now.

Thanks for your help. I'll keep you updated.

Good point. Before the corydoras similis, I had a juvenile angelfish and mini snowball pleco in this quarantine tank. No problems with them.

Good point. Before the corydoras similis, I had a juvenile angelfish and mini snowball pleco in this quarantine tank. No problems with them.

No problem, I appreciate your help. I can't remember exactly, but I think the Sterbais had all passed by November, so it was probably late November or early December. I had another group of fish (same vendor as corydoras similis) that were in this quarantine tank in early January after the lysol and before the corydoras, and they are still doing fine now in the display tank.

I lost a tank of fish in 2018 to Mycobacterium marinum that was confirmed through necropsy by an aquatic vet. The vet recommended using lysol to kill the myco at that time, so I used it for this quarantine tank out of an abundance of caution. It was thoroughly rinsed and dried before being used again. Thanks Tony, I definitely agree with that. Appreciate your help.

Thanks Tony. Yeah, I see that it's quite a lot to put them through. I've been reading a lot of conflicting information. I contacted an aquatic veterinarian but stopped getting responses, feeling desperate as fish keep getting sick and dying.

Changing water at least twice a week. I started the salt March 6, upped it March 9, and have been keeping it at the 1 tbsp/2 gallons since then (10 tablespoons for 20 gallon tank). I would change 50% of the water and then add back in 5 tablespoons of salt, putting the salt in a fish net suspended at the top of the tank and letting it dissolve through the net. I've had problems with corydoras since September 2023. I had a group of Sterbais from a different vendor who all died in quarantine with similar symptoms to the current ones. I didn't use any salt with that group, but I did use Maracyn and PraziPro after being advised by that vendor. I didn't know what the cause was, so I tore down the quarantine tank, disinfected with lysol, and started back up with a new seeded sponge filter in December 2023. These corydoras similis are from a different vendor. None of the medications were used prophylactically; I started after the fish were floating to the top of the tank, losing their ability to swim, and dying. The last medication was Expel-P on March 21, 25% water change March 22, and did not add back salt.

Thanks. The most noticeable symptoms have been redness and floating to the top of the tank, struggling to swim. Some have had white spots, but they also get the fine sand on them and it can be hard to tell. I keep the light off to try to keep stress low. I started with 1 tbsp/3 gallons on March 6 and increased it on March 9 after floating/dying started. I wasn't sure if I was dealing with a bacterial infection and/or parasites, and thought salt would be safer than antibiotics. They are juveniles sourced from an online vendor and 13 of the original 23 are alive.

I've lost 10 out of 23 corydoras similis in quarantine since January 25th. Some of them had some redness before dying, some rapid breathing, some loss of fins and barbels, trouble swimming, but I haven't figured out a clear, consistent reason. They're in a 20 gallon long quarantine tank that has been set up since December 2023 with sand substrate and a sponge filter seasoned from my display tank. Water is conditioned with prime, and I change 30-40% of the water at least twice a week. I feed mostly Sera wafers. I've tried aquarium salt up to 2 tbsp/gallon, PraziPro, Flubendazole, and Expel-P over the past two months with no improvements. I first gave the Expel-P on Thursday, March 21, followed up with a 25% water change 24 hours later, and have lost four more corydoras since that. I check the water parameters with the API master kit and parameters have been stable throughout the past two months. 0 ammonia 0 nitrite 20 nitrate pH 7.4 KH 35.8 ppm GH 53.7 ppm Temperature 79F Has anyone had success treating something similar?