Red Tail Shark - Water Change

[Prototype X]

I decided to do a full water change on my 55 gallon tank. I cleaned it an put half old and half new water in.

Then 30min later i put my 3 small fish in. They immediately swam to the bottom of the tank and turned on their side. 10 minutes later they were dead.

I put my red tail shark in for 1 minute and when I saw him turn over immediately I put him back in his holding pot. He acted normal but started bleeding from his gills and turned white. Dead 30 minutes later.

This RTS has been with me for four years. What the hell is wrong with my tank?

 

[CAPSLOCK]

Did you use anything to treat the water with? If you have city water (versus well water) it is possible maybe they also flushed something into the lines that you weren't aware of.

Or, did you use something inside the tank to clean it? Some kind of cleaning product? Windex used on the glass can be fatal, if any misted into the tank.

Those would be my guesses, a temperature difference wouldn't do that, nor would normal clean water.

 

[Joshjr619]

You might have done too much. Cleaning the whole tank and changing half the water could've killed most of the beneficial bacteria. I could be wrong though, check ammonia levels ASAP.