Over Heated Tank!

[FreshwaterFish]

Hey guys,

Yesterday night i came home to find two thirds of my fish dead and the temperature well above 30 degrees celsius...
I have a 60 litre tank and recently installed a new Fluval U2 filter, originally it was blowing onto my heater - could this have affected the thermostat, causing a massive heat up? I turned the heater off over night and now the water is back at the correct temperature.

Secondly, before the deaths the fish were often just swimming at the top as if for air, however I have an air pump and even with that on they still stayed at the top. My remaining fish are doing the same and not swimming much - HELP!?

 

[phoenixgsd]

how recently did you change your filter, did you change over the media also? what are your water stats?

 

[WILDER]

Did you transfer the old mature filter sponges into the new filter.
Can you post your water stats please in ammonia, nitrite, nitrate, and ph.
Full stocking list.

Immediate water change.
Move your heater below the filter so the outlet pipe now hitting the heater.
Keep a look out for whitespot. columnaris, swim bladder. As fish can come down with any of these three diseases when
temp has altered dramatically.

Sorry for you losses.,

 

[FreshwaterFish]

I changed my filter just over a week ago but was not able to transfer the media due to it not fitting. Now I only have 2 platys and a male guppie left, with the water conditions being:
NO3 - 25
NO2 - 0
GH - 16d
KH - 13
pH - 8
Ammonia - 0 (will re - test tomorrow)

I performed a 30% water change today and repositioned the filter

 

[WILDER]

So the tank cycling if you never used the mature filter sponges from your old filter.
Did you squeeze any good bacteria from your old sponges onto the new filter sponges?