Last thurs. I had a neon tetra that was dying. I took him into the LFS because I wanted to know what it was that caused this and if it was contagious. The LFS person immediately said that it was a bacterial infection and to use sulfathiozole. she was unclear about the dosing and the package just says to use until every 3 days until you don't see any more symptoms.

Well I haven't seen any symptoms in any of the others; I was just doing it because the lady said that what the neon had was contagious and I wanted to make sure the others didn't die. I dosed according to the instructions on the label, took out my carbon and have been checking the fish often. It's now been 3 days and still everyone looks OK and is acting OK. I called Seachem (the company that sells sulfathiozole) and asked if I should do a second dose. She said that if I'm not seeing any symptoms, then stop the treatment, and put back the carbon. I did a weekly water change just before I started the medication last Thurs.

Just wanted to make use that you guys agree. Has anyone had experience with a bacterial infection and/or using sulfathiozole.

I have never tried that product. The LFS may have just wanted to sell you something. Did the neon die? I would have been hesitant about using something that someone recommends yet they have no clue how to use the product. Doesn't seem right to me.

Were there any visible signs on the dying fish or any of the other fish in the tank?

Sulfathiozole is a good medicine and safe for fish and nitrifiying bacteria. If your symptons are gone you are probably safe to stop treatment. Do a water change and replace carbon!