Mass Die-Off

[Twoapennything]

Can I get your thoughts on what occurs when there is a "mass" die-off of fish in a tank?

We've been trucking along doing okay here, and then my big mystery snail died. Then my neon tetra. Then my African dwarf frog. This is within the last two days.

Nothing's changed as far as I know. Ammonia, nitrite, and nitrate levels are fine. pH is slightly low but not dangerously so. I've been doing weekly PWCs. The temperature has remained steady. The filter is working. None of the fish appear to be diseased or ill.

Does this kind of thing just happen? I know three isn't a ton of fish, but I don't have a lot of fish to begin with (13, now 10).

 

[Crepe]

How big was the tank, what are you using for tests. How frequently did you test and what were all the readings you took.

 

[Twoapennything]

I use the API master test kit. I'm sorry, but I don't remember the exact readings, except they were within normal range. I should have written them down (I keep a log and try to enter all my testing readings every day, but I sometimes miss a few days).