surfs - I wish I had a crystal ball to look into, but I don't. Sometimes even when one is standing right there it's next to impossible to determine an exact cause. Don't get me wrong, gastrointestinal issues (which result in bloat) can indeed be triggered by diet, I just don't think that it's as common as many believe. pH isn't an issue, I've seen every species of fish imaginable raised in pH 8.0
Just keep in mind that an outbreak of spironucleus (which often leads to bloat) can start with a single weak fish, and within a few days the entire tank can be wiped out.
But what strikes me odd about your situation is that they were all fine one night, and the next morning they were all dieing. This is not what happens when fish have a dietary issue, or any type of problem that leads to a classic case of bloat - typically the first thing that happens is a fish refuses food, then begins lurking off in a corner by itself, then sans any type of treatment they begin to become sicker, until their organs begin to fail - at which time they take on a bloated appearance, and shortly after die. The entire process typically takes at least a few days, not a few hours.
What you have described sounds to me like one of two things, either the food from the day before had become rancid, causing immediate distress, or somehow a toxin entered your tank. (air-spray, something off of your skin, etc)
A tank full of fish would never be swimming normally, eating normally, and then overnight all start dieing off one after the other - from any kind of dietary issue, unless the food had some kind of toxin in it.
Just keep in mind that an outbreak of spironucleus (which often leads to bloat) can start with a single weak fish, and within a few days the entire tank can be wiped out.
But what strikes me odd about your situation is that they were all fine one night, and the next morning they were all dieing. This is not what happens when fish have a dietary issue, or any type of problem that leads to a classic case of bloat - typically the first thing that happens is a fish refuses food, then begins lurking off in a corner by itself, then sans any type of treatment they begin to become sicker, until their organs begin to fail - at which time they take on a bloated appearance, and shortly after die. The entire process typically takes at least a few days, not a few hours.
What you have described sounds to me like one of two things, either the food from the day before had become rancid, causing immediate distress, or somehow a toxin entered your tank. (air-spray, something off of your skin, etc)
A tank full of fish would never be swimming normally, eating normally, and then overnight all start dieing off one after the other - from any kind of dietary issue, unless the food had some kind of toxin in it.
