mysterious mass death

[Kittycat]

I lost a lot of guppies and some platy fry today, and I don't know why. I don't see any signs or symptoms of illness, etc. I don't have water testers, so I can't say for sure how those are, but I did a big water change, and will continue doing the same tom and after. I did notice that the weather was rather hot, the thermometer in the tank said 90 degrees F, though I'm not 100% sure it's accurate. If it is, could it be the cause of death? Or are fishes not yet likely to die at that temp? If it is the possible culprit, any tips on lowering it?

 

[WILDER]

With high temp bacteria can thrive.

 

[webcat5]

Most fish like the temp. between 70 & 80. 90 seems way to high.

 

[Tropjunky]

"big water change" exactly how big? anything over 50% is drastic and should only be done if u've OD ur fish and if there are high ammonia levels.

i suspect it's this water change coupled wit ur tank temp that caused this but without water tests i can't say for sure

 

[Tokis-Phoenix]

I would buy some test kits for ammonia and nitrite and nitrate at least as they are realy essential, guppys and platys prefer to be in tanks at 24degrees.
Keep doing some water changes and slowly start turning the temp down.

 

[Kittycat]

Thanks for all the help. I did the 30-40% water change only after I found the dead fishes. I think I found the cause of the deaths--my canister filter was not sucking in water so the filter was in essence not running.

 

[Tropjunky]

Hope u don't have anymore problems and sorry to hear about ur fish hope the rest of them saty alive and swimming