I'm bad at expressing things succinctly so I'll try to post the immediate problem as simply as I know how and then afterwards add a more detailed account of how it started and what I've tried already for those that want/need more info. Even still I will most likely make this too long of a post by normal standards and I apologize for that. Essentially I have two glowlight tetras that got or have either Ich, Coloumnaris, even NTD, or likely a combination of two or all of them... I tried to get it handled pretty quickly after noticing it however I fear that it has done to much damage that at least one may not ever be able to have a fulfilling life even after all of the issues are cleared up. I'm also running out of ideas of what to do to make sure they are both completely clear of disease, healthy, and safe to return to the general population tank. They are in a 5gal tank by themselves A HOB rated for 10-20gal (I think) with the flow turned low and do not seem to have trouble with any current. A circular air bubbler to keep the water well oxginated. Very sparse gravel substrate, mostly just enough to hold down three artificial plants to help them feel more secure and safe in the tank as well as a small piece of driftwood to also hopefully help them feel safer. It's hard to tell how much or if they even are eating but I think they are some tho nowhere near like they did before getting sick. They behave relatively similar to how they always have with the exception of not going after food the way they used to and they seem to alternate between hiding and hanging out in the open in one place for awhile, but do on occasion dart around place to place, both behaviors that they did previously only I'm more aware of it with just them in the tank so it seems amplified by that I think. The water didn't have much of a chance to cycle before we had to QT them and since the medicines kill of a lot of the bb it's hard to know exactly what is happening. The ammonia has fluctuated some but I use Prime in proportion to each water change to keep it from becoming toxic. It normally reads at a .25 but has hit .5 and even up to 2ppm usually when I test too close after adding the medication. Nitrites are at 0 except for one spike that I hoped was just signaling that some of the water was going thru the Nitrogen cycle. Nitrates are at about a 5 or less though again at least once they did read a 10/20 (there is almost 0 color difference on that API chart between the two!) following the nitrite spike I believe. PH is around a 7.4 typically tho it is seems to range closer to 6.8-7.2 after adding the driftwood piece. Temperature is at about 78° F tho I did raise it higher in the beginning when we thought it was Ich more than cotton rot. (I sincerely hope that isn't part of why or how they ended up as possible permanently disfigured as I fear they may be now.) I have also used on occasion both Stability and Stress Guard by Seachem after water changes or before adding medicine to the tank tho I worry about adding too many chemicals, even "all natural" ones like the -fixes, at once and screwing up the treatment and/or making the poor guys sicker or hurt more. I really feel I've let these guys down and am very sad, mortified, and embarrassed to even post pictures that might be needed to get the best advice because I very much fear that I'll be considered an awful person who should never be allowed to be entrusted with fish :/ and I'll be excommunicated from the forum after my first post! However I owe it to them to post them if need be to help figure out what the best course to go thru with is... (I also know now that they would be happier being in a group of closer to 4 or 6 even rather than two, but obviously can't conscionably add other fish into the QT while they are sick.) I have a lot of pictures of them which I took while they were in a "ParaGuard" dip that I can post once I know how to do so on here if they are needed. Extra details: I have had two glowlight tetras in our friendly tank which consisted of mainly other "Glo" tetras and two ottos, along with a few shrimp that have come and gone, all with its own high and lows and the awkward nitrogen cycle learning curve. We managed to get through that but ended up, ironically, having a slightly overcrowded tank because of getting a larger tank from my sister. Since I didn't want to repeat my mistake of not cycling it completely before adding any new fish waited a while to get any new fish for it. However when we started having a bullying probably in what was set-up as our QT tank that we had added an "adopted" guppy that had been my nephew's who probably wasn't the best fish keeper as he's a typical 8yr old lol. So we had to move a couple into the mid sized tank for awhile and all seemed fine for quite awhile. All the tests came up fine except that the nitrates were a little high, even though they I was keeping up with WCs using a gravel vac it wouldn't seem to budge no matter how little I fed or much I cleaned. That's a problem I'm still working on, but I also think it might be what led to the two glowlights becoming sick. One of the two has always had a messed up looking dorsal fin which I now suspect may have been caused by having an earlier case of fin rot while at the pet store or while still at the previous owners house, but I never thought it could be a sign he could be a carrier and possibly have a weekend immune system because of that untill this happened. None of the other fish (tho mainly also all tetras tho different kinds) became infected and thankfully the big tank had finished cycling so I could move the "bully" and a few other fish and shrimp/snails into the biggest tank (it's only a 30 so I know that it's in no way what most people consider a "big" tank but it's our biggest for now anyways so please excuse the misnomer) easing the overpopulation in the medium (10gal) and allowing is to put the glowlights into the 5gal QT and treat them more vigorously since there were no scaleless or invertebrates to worry about. I've tried ParaGuard treatments and also dips twice, Salt once, quICK cure, mela and pima "fixes", a generic brand parasite remedy, and finally kanamycin. All of these at different times for the specified amounts according to the labels and while do partial water changes every few days or so depending on the treatment and results it showed etc. I'm sorry I don't have a better kept log of what I did exactly when. I never expected that it would be such a battle and that they would either heal or succumb to whatever it was. The first medicine that seemed to help was the quICK Cure but only for the first treatment, it didn't seem to do much after that. The ParaGuard seeneed to help when used in a dip situation, but ultimately the kanamycin worked the best tho the directions of when and how long to use it aren't very clear and even it can't seem to completely get rid of all the spots. I'm also just not sure if either, but one especially, will ever be able to function or have decent quality of life as his poor face and mouth have taken a great deal of damage sadly. I love these two little guys and have had them almost a year now and hate losing even things like ghost feeder shrimp, so the thought of them dying is heartbreaking yet so are both the idea that they may be suffering and might live but always have difficulties living anywhere close to a normal life, however dealing with the idea of actually having to euthanize, or make the call to do so, is what stopped me from pursuing a career as a vet back as early as high school and that hasn't changed so I am very torn. I feel very guilty that they got and are sick and could be suffering because of something I did or didn't do and almost embarrassed to have to post pictures that shows just how horrible of a fish caretaker I have been.