I'm in desperate need of help. My Kuhli loaches are all dying horrible, violent deaths and I can't figure out whats causing it. I've been researching for hours and I have found nothing on what could be causing this.
When I first received my loaches, they appeared healthy. But after the first day one loach died. It didn't have any psychical signs of disease so I checked my water quality and everything was fine, 0 ammonia, 0 nitrite and 20 nitrate. I just brushed the death off as stress from being shipped (They were ordered online) or that it had an internal problem. A week later, one of the living loaches appeared to have a small scratch on his face. It looked like he had scraped a himself on something in the tank. It wasn't serious and he was behaving normally so I left him in the tank, thinking it would heal on its own. Well, when I woke up in the morning he had died. His body looked horrible. A huge chunk of his face was gone, parts of his body were bright red, and he had a white film that was coming off of his body. The chunk of missing face was exactly where his scratch was. I unfortunately did not take any pictures of this loaches body.
For the next few weeks, I was closely examining the living loaches. They were checked for signs of disease and injuries daily and they were perfectly fine and healthy during those few weeks. But, a few days ago one of the loaches had a scratch on it's face that looked exactly like the one the loach that died earlier had. I quickly put him into a quarantine tank. I had no idea what disease this was, so I started treating him with Mardel Maracyn 2 since it cures a somewhat broad range of illnesses. His scratch quickly became a chunk, and that chunk gets bigger and bigger everyday. His barbels are getting shorter and some are completely gone. There's barely any part of that face even left and he has completely stopped eating, but is alive.
Pictures of loach with missing face: http://i61.tinypic.com/nq8ug.jpg http://i62.tinypic.com/1zlc1ow.jpg
I couldn't really get a good picture because he wouldn't stop moving. The missing chunk is directly in front of his eyes and you can kind of see it in these pictures, but it's a much more severe injury than what these images show.
Yesterday, another one of the loaches started looking sick. He had a single white patch on his body and I moved him into quarantine with the other sick loach. The patch looks nothing like Columnaris or Ich and I couldn't find anything that matched the description of the white patch. He started to rapidly deteriorate, the white patch spread to his sides and belly, he couldn't swim anymore and would occasionally makes these horrible seizure-like twitches and shakes, he had a a black bruise-like spot on his side, and he had small patches of missing flesh on his body. He died last night.
Pictures of dead loach: http://i58.tinypic.com/2wme8ok.jpg http://i58.tinypic.com/30m4qix.jpg http://i57.tinypic.com/21od55w.jpg
My tank is 20 gallons, cycled, (0 ammonia, 0 nitrite, and 20 nitrate. I use the API freshwater masters test kit) and has live plants. It is stocked with 1 male Betta, 6 neon tetras, and 3 kuhli loaches (I originally had 5. When the first loach died, I purchased a replacement. But after the second one died, I didn't add any more loaches in fear that it would get sick and die as well. Last night I lost a third loach) I do 30% water changes once a week and always remove uneaten food and fish waste.
My tetras and betta are all healthy, it's only the loaches that are being affected. I don't know whats causing this or why my fish are getting sick in the first place. It's really heartbreaking watching this happen to my fish. If you have an idea of what this disease may be, tell me please. I don't want to lose any more fish.