My blue long-finned danio Dash died tonight. I knew for days he was dying, but I just didn't have the heart to put him down since he was my favorite fish. I know I shouldn't have let him suffer, but I wanted to believe he would somehow recover. Of course, he did not.
My pH has been very low (6.0 or less), my temperature high (80-84) my GH hardness between 30-60, my KH hardness between 0-40, 0 nitrites, and between 40-80 nitrates. I am working on recovering my pH with advice from Byron.
This past weekend was when I noticed Dash's decline. He was thin, and he was hiding and swimming in place at the bottom. After researching, I came to the conclusion that he was likely suffering from internal parasites or tuberculosis.
The internal parasites seemed most likely to me, since it made sense that I wouldn't have immediately noticed his gradual thinness since he had been eating normally before. I didn't notice his health until after my green glofish died last Monday or so. He had gotten stuck in the filter intake twice and seemed bad so I had put him down. Someone pointed out to me that the glofish must've been in poor health already to have gotten stuck. If the case is parasites, it's possible that they got to the glofish, weakened him, then went to the blue danio Dash next.
As for tuberculosis, I didn't want to believe it. No one does. So after noticing his obvious illness over the weekend, I got parasite medication (API General Cute Anti-Parasitic Fish Medication). The instructions said to remove the filter cartridge which I did, leaving the little biological filter in with the filter box running. It also said to keep aeration so I kept my air stone on. I had read elsewhere that raising the heat helps with killing parasites, so I stopped putting frozen water bottles in the tank which I had started doing recently to bring the temperature down to 75-58.
I started with that medication on monday. He was already worse though. He was now sitting or lying on the gravel instead of swimming in place, and his spine was showing a bent as I have seen happens in tuberculosis. I should mention I did not remove him from the tank during this treatment, since if it were parasites, I figured the other fish could have it too. (Other fish being 1 other danio and 2 otos.)
The following day he was worse still, even more bent and twitching and flipping around at best, unable to swim straight when I would poke at him to move. (I would occasionally poke at him gently when I thought he might be dead, because he seemed so lifeless.)
Then today I did the second dose of the medication, in addition to adding salt. A lot of salt in fact, a tablespoon of non-dissolving salt and 2 tablespoons of dissolving salt. I was feeling desperate.
Then hours later when I checked on him, I realized that the slight moving of his body was not from his panting and twitching but only from the movement of the water. I pulled him out of the water to make sure. And sure enough, there was no gasping for air, no movement. I examined him with a flashlight to make sure there was no gill movement. I wanted to be absolutely sure. And alas, he was dead.
I took photos of his carpse (see what I did there?) so I could show you all and get an opinion of what caused his death.
So let me know what you think please. If it looks like parasites killed him, then I would see the medicine treatment on the tank through completion, and if it looks like tuberculosis killed him, then I'll stop the medication and just do a heavy water change I guess.