It's been an anxious day today. The kids and I had just got back from a walk when Catherine noticed that Calico, our fantail goldfish, was bent up and resting on the bottom of his tank. He looked horrible.
She began to cry because she knew what the likely outcome was. We had a beta a few years back that got sick and we euthanized him by freezing him in a baggie of water. i think she was expected that to be my suggestion this time around. But this is Calico and Calico has been with us for 3 years now. He has a 10 gallon tank (really the minimum you need for one goldfish. Never put one in a goldfish bowl!) and gets regular treats of cooked peas. He's a special fish.
So we put in some medicine in case it was a fungus or parasite. Then we did a water change, about 50% in case it was water quality. Which it turns out, it likely was. We noticed black marks on his fins and black marks are scabs where a fish has been scratched or burnt and is healing.
What we peiced together is this - Harry dumped a ton of goldfish food in one day a couple of weeks ago. I cleaned it out and did a water change then (suction out a percentage of water and replace with fresh stuff) but hadn't done one since. I was negligent. I'm guessing the decomposed food caused problems with the chemistry which resulted in ammonia that burned Calico and nitrites that caused his current problems.
If he's still alive in the morning I'll run out for a testing kit and some aquarium salt. I'll also change the water again. I'm going to give this little guy every chance I can.