The Puffer Forum

I came home today to find one of my dwarf puffers on the bottom of the tank almost black and not moving. So I quickly move him to see if he's dead which he isn't. My other puffers are fine. When watching him yesterday he seemed fine, swimming around the tank like normal and eating like he usually does. So I'm just wondering if anyone knows what would have had such an effect on him in less than 24 hours without effect the other puffers. He also seems to be having spazms from time to time too.
Well while writing this I just checked on him again and he has passed away. My tests are showing zero ammonia and zero nitrates. Any ideas would be greatly appreciated as to what could have happened.
Im just glad my other puffers are doing well though I will definately be keeping a close eye on them.

Can you please answer all of the questions in red?

Well, according to the numbers you have given us, your biofilter may have crashed. I don't know how advanced you are in aquarium knowledge so I'm going to start from the beginning. When you cycle a tank you are growing bacteria that converts ammonia to less harmful (but still nasty) nitrate then to even less harmful nitrate. If your tank is properly cycled you should see some nitrates as the end product of the nitrogen cycle. So, having 0 ammonia, 0 nitrates are odd readings. One big factor in the results could be a bad nitrate test, they are real easy to do incorrectly (I've done it wrong and still do at times), and you need to follow the directions very carefully. I am going to ask you to re-check your nitrates and also do a nitrite test. If your biofilter did crash and you truly do not have ammonia and nitrates you should have nitrites showing, this will give an idea of where the biofilter is.

Also giving answers to the rest of the questions in red will give us idea of anything that went wrong.