Please Help. Sick 12" Pleco


New member
I know this isn't reef related, but you guys are awesome and I trust your opinions more than other people's facts. I'm sure like me a lot of you started out with freshwater tanks and possibly still have some old friends. This guy is 12" long in a 95g tank, and has been with me for almost 5 years.

He started getting a spot just below his dorsal fin two days ago. I thought at the time that he got stuck under a rock and rubbed it raw so I did a partial water change (w/ RODI) and squirted some seachem stress guard around him. Then today I noticed his whole body is looking horrible. I can see bloody patches between scales, and it almost looks like the outer layer of his scales are falling off. I have Kanaplex, Metronidazole, Methylene Blue, Melafix, Pimafix, Stress Coat, Stress Guard, etc... but I don't want to use anything until I know what's going on. Here are a couple pics of him and his partner (who is fine... for now.) Thanks in advance, mike


  • IMG_20150201_192335743_HDR (800x450).jpg
    IMG_20150201_192335743_HDR (800x450).jpg
    82.7 KB · Views: 0
  • IMG_20150201_192614909_HDR (800x450).jpg
    IMG_20150201_192614909_HDR (800x450).jpg
    75.7 KB · Views: 0
  • IMG_20150201_192954023 (800x450).jpg
    IMG_20150201_192954023 (800x450).jpg
    75.7 KB · Views: 0


New member
I have larger pics but I didn't want to scare people away too quickly. Let me know what you can tell from these and I'll upload another one if I need to.

I spent the longest time wanting to move my 55g reef into the 95, but I was waiting for the old timers to be on their way. After I setup my 180g reef, I accepted the idea that I'd keep this one freshwater. I really don't want to have to rethink this again.

thanks again,


New member
I have two freshwater tanks beside my reef tank - my wife likes the plants and wanted those tanks for feng shui ;)

Unfortunately I'm not an expert on freshwater diseases besides ichthyo and nematodes (you get to deal with the latter a lot if you try to keep wild West African dwarf cichlids). In general I found freshwater fish often dying too fast to even get to a treatment.
But on the other hand you usually can treat in the tank as long as you don't have invertebrates like shrimp or snails.

According to my books this could be a parasite, either flagelata or cliata: chilodonella, trichodina, tetrahymena, costia, hemiophrys or tricodinella.
You would need a microscope to identify which it is.
They are the freshwater equivalents to brooklynella, uronema or trichodina. The speed this developed kind of sounds right for these but would also fit for "just" a bacterial infection.
It seems you can treat these parasites with a mix of formalin and malachite green (Rid-Ich Plus for example).
You may also need to treat the opportunistic bacterial infections that usually go hand in hand with the above parasites.

I hope one of the fish disease experts here can chime in and help more.


New member
Thanks. I guess I should give some more info incase it helps. My water parameters are all fairly normal. Temp 77, Nitrates 30, Nitrites 0, kh 80, gh 180, and the ph was a bit low but I got it back to 7ish.

I have a couple ghost glass cats, guppies, and gouramis that stay up at the top. Middle column are 4 saucer sized silver dollars, a pair of 9" bala, and a huge 8" fan tail goldfish. On the bottom there are the two plecos, 8 Cory cats, and a large siamese algea eater. No new additions in the last year or so other than baby guppies.

Before someone comments on the bio load, I have a 50g sump / refugium below the 95g display tank. These guys have all been together for several years and I've never seen anyone pick on anyone else. I check my water every month and do regular water changes. I've always had low pH and high GH, but I don't see that playing a part here. My GH has been going down since I started using RODI (last year) and I add some pH buffer with water changes and top offs.

I lost a gourami, a german blue ram, and a jack dempsey to some mystery fin rot/bloating plague a while back, but other than that it's been a healthy system for 5 years. I've been lucky in my other tanks too (especially the reef) I haven't really had the chance to treat disease much and I hope I don't get the chance.


New member
I felt I had to something so I ended up giving him kanaplax last night since it helps with fungal and bacterial infections. Then this morning, he looked even worse. I found my paraguard on the back of the shelf and dosed the whole tank with that.

Unfortunately, his only symptoms now are being sealed in a ziplock bag while I decide how to dispose of the carcass. :thumbdown

Thanks for the help, but I still don't really know what happened. I liked the list that emcmilla posted. Amazingly enough, I never thought about salt... I always used to add salt with water changes to my live bearer tanks. Once I got my reef going and started using RODI I kinda forgot. I had R/O Right, and other supplements, but forgot about salt. I know it's not a salt treatment, but at least it's something.

Live and learn


New member
Aww. I'm sorry you lost him. I'd bookmark the page I linked to maybe as a reference. I remember plecos were my favourite in my FW tanks. Again, I'm sorry he didn't make it