Bugeyed

I haven't been around in forever... lots of life changes (and I lost my password ) I've had a recent issue that I'd like some advice, but first a bit of history. Sorry this is long...

Purchased Chubbs (black moor) and Dahmer (calico fantail) well over a year ago and have been keeping them in a 15 gallon (I know, a bit small) tank. Dahmer has absolutely thrived and has grown... very beautiful fish! Dahmer never did so well. He never really grew much and I think was just a "runt." He never was really sick, but never acted well, either.

Anyway, about a month ago, Chubbs went to fishy heaven. No warning... just came home one day and he was dead. I continued to change water (25% changes) and my water was always spot on... nitrites, nitrates, ammonia, etc.) Perfect!

So I purchased a new fantail from the local pet store (PetCo) and within days, Dahmer was hiding and resting on the floor of the tank. The new fish (Magnum) was a bit more aggressive but not to the point of injuring Dahmer. Dahmer also never rested or hid when Chubbs was around. He seemed otherwise healthy and active... just sometimes rested on the bottom of the tank. Doesn't seem to be gasping or rubbing against anything.

Then we noticed that Dahmer had a "bubble" on his spine, right where his tailfin starts. It was about 1/3 the size of my little fingernail. I researched bubbles and thought maybe I added too cold of water, etc. Then, two days later, the bubble was gone!

But wait... now the bubble is on Magnum... on his side... and it's green and has tiny leg like things... and it's MOVING! We researched it and realized without a doubt it was a fish lice! I caught Magnum and removed the singular lice from him. It came off very easily, and then dropped him back in the tank. As far as we can see, there are no more.

We purchased some parasite medication, which includes fish lice, and will begin using it tonight. While at PetCo to buy medication, I looked at the same tank from which we got Magnum, and sure enough... there was a fish in there with a very visible fish lice on it! I promptly told the employee working in the fish area.

But I was curious to know if you had any other advice...

Thanks for reading this novel!

Chief_waterchanger

Frankly;

Stop buying fish at Petco would be my advice. (Some people call it deathco, but I will not do that due to liability issues because slander is against the law in the USA.) Also, a 15g for 2 goldfish is beyond a little small. Most people suggest 20g for first goldfish and 10g for every one after that, I disagree with them for several reasons, one of which is the size of the fish. At full adult size take 8-12 inches of fish and try to give it room in a 20g to swim around and turn around comfortably... take a ruler (12 inch) and see just how far you can move it through the tank before having to turn it around, not far huh? I would keep goldfish in nothing smaller than a 55g for the swimming space. Sounds like you did great on the parasite detection, though. If you are going to continue to keep goldfish I would suggest a larger tank.