Back again

[tarajo]

Last night i went to bed and all was well in the tank... this afternoon i went to do the water change after work and i had 5 of 7 danios VERY dead floating in the tank. so i am now down to 5 fish total.. 2 remaining danios, 2 black skirt tetras and one oto. I checked my water and every thing was fine, i have NO idea what happened to these 5 fish, my tank is right by my bed so i know last night they were all fine. any guesses what could have caused these sudden deaths? I am absolutely heartbroken, as i have had this tank up and running since right after christmas and until today had lost only one Oto and that was months ago...
any ideas would be appreciated, i am not going to restock for awhile in case it is something in the tank itself, i will wait and keep a close eye on the survivors

[rich311k]

What exactly are your parameters? Any chance the temperature soared or dropped significantly? Is it possible something accidentally got put in the tank?

[tarajo]

i can't think of anything that could have gotten in the tank, it is in the corner of my bedroom, so there isn't a lot of traffic or anything, it has been hot here, but it doesn't seem to have affected the tank in any real way. it is within a degree or 2 of where it usually is. my ammonia and nitrite were 0 and the nitrate was below 5ppm but not sure where, the color chart only shows 0 and then up to 5, and it was water change day so i don't think that would be a problem. i am just so upset about this, i almost wish my ammonia or nitrate had been high so i would at least have an idea as to what caused them to die.

[Devilishturtles]

Sorry Tara

I'm with rich. It's almost impossible to know what happened. The temperature could have climbed significantly and then dropped. How are the other fish looking?

[tarajo]

So far still so good, i am keeping a close eye on them, but they seem to be behaving normally so far