AquaMom

Sorry for the re-post but I am running out of ideas...

I had 7 neons, all doing very well in a nicely established 120 gallon tank with pristine water quality when I ignorantly decided to add 12 without quarantining them. I lost 8 of mostly the newly purchased neons within a week. Most of them would appear just fine until one day they wouldn't school, the next day their head would turn gray and their eyes would bulge, the next day the red strip would turn yellow near the tail end and the tail would seem to explode into a yellowish pustule like ball with no fin and then they would soon die. After it happened a few times I tried treating a couple of them in a separate 10 gallon with Maracyn and Maracyn II and none of them survived. That was over a month ago now. Two weeks ago, I noticed I have another one that's now showing the same characteristics. I am pretty good with diagnosing disease but I have no idea what this is.

I waited a week to see what he would do on his own because I know they get stressed when not in a school so I was hesitant to separate him. He didn't get worse but he didn't get better on his own so finally I separated him into a cycled 10 gallon and did two rounds of Malachite Green for parasites with absolutely no effect.

I have been doing Maracyn with Maracyn II for a week now thinking bacterial and no change. I added 5 new neons to the quarantine tank to reduce his stress of not being in a school. They have been well for 3 days now.

I started feeding anti-parasitic foods two days ago too just in case it was internal parasites. Today, he is actually worse. The tail looks much more inflamed and yellowish, the yellow has actually claimed most of the red stripe on him tail, he looks much more wasted away and now his mouth almost appears stuck open with a white pustule on the top lip. Definitely not NTD though from what I've read.

I have no idea what this is and no idea what to try next. I am pretty sure this poor little guy won't make it but a few more days but if there is anything else that you can think to try, please let me know. Since all of those 12 sicklies I bought at the local fish store aren't all dead yet I have a feeling even when this latest one dies I'm not out of the woods yet.

AquaMom

Another one in the main tank is developing the yellow tail. No pustule yet on him but it's a matter of time. Here is a photo of the one with the big lump that is bad off in quarantine and another in the main tank that is starting to turn yellow.

http://app5.sellersourcebook.com/use...ick_neon_1.jpg

http://app5.sellersourcebook.com/use...ick_neon_2.jpg