My beloved Goldfish Tango, who is a little under a year old, was lying on the bottom of his tank this morning. This came as a shock since at 10:30pm last night he was up and swimming normally, and there have been no precursor signs of illness. He has no fin rot, no blotches or blemishes or bulges, and has not been lethargic. I am desperate to help him; he's my personal favorite of all my 25 fish!
Specs on the tank: 10-gallon planted tank with Tetra 5-15 filter and extra air stone for aeration. He and another similar aged goldfish are the only inhabitants except for a couple of rams-horn snails. Ammonia and nitrite are at 0ppm, and the nitrate was at 10ppm.
I realize that this tank is way too small for goldfish, but we just don't have any other room for another tank and I didn't want to put my goldfish in with my warm water fish in the 55-gallon. I had thought of giving the goldies away but was concerned that they would get put into a bowl or something else even worse than a filtered tank. Thus they are where they are until I can figure something else out that will be better. But maybe I am killing them in the process...
Some info you need to know about Tango:
1. He was the "starter" fish in his tank, so he's been through the ringer with the cycling process. (I've learned a lot about goldfish and tank cycling since then, thankfully, and will never again use goldfish to cycle, nor will I put a goldfish into such tiny living spaces.)
2. He also has a deformed mouth, so I am concerned that he cannot take in the needed water to oxygenate his lungs - almost like he is slowly suffocating due to the deformity. He might also have trouble eating; he just sort of vacuums up his food rather than being able to bite whatever he wants. I have to make sure to give him flakes and such that are easy to suck down.
3. For some time now, his color has been disappearing. I've been told that Goldfish just change color as they age, but this is really more like fading/disappearing color, not a changing color. His forehead is now nearly translucent rather than the dark, rich orange he used to be (see my profile picture to the left to see what he used to be like). Whether there is anything wrong there or not, I do not know.
Can anyone offer suggestions? He might have even died while writing this because he was so bad when I sat down to type. So far I have done an emergency water change and added a little aquarium salt, Melafix, and Pimafix. There was no change in his behavior after this. I have also heard that you can feed a goldfish an epsome salt crystal inside a shelled pea to help with "sinking," but I doubt I could get a pea into his pin-hole-sized mouth even if it were the only thing that would save him.
I will go check on him now and see how he's doing.