


It started when i found one young zebra about 3 cm dead. When i checked the tank i found several more dead , and several young that where in trouble. They all seemed to have lost their swimming capability, just tumbling around on the bottom and shaking their bodies. A few of them altso running around in the tank like crazy.
I am totally lost, all the adults where fine,
actually one pair was spawning at the time.
I checked the water values and found that my No3 was a bit high, but the NO2 and Ph where all fine. I did some ekstra water changes the two following days and things looked allright, until today.
Today i found several more dead and some in big trouble. Checked the values again today, but everything seems ok, the no3 was now at about 25mg/L and that should not be deadly at all.
The dead ones range from newborn to eight monts old.
I carried out a 50% water change tonight, and can only prey that the few i have left will survive.
I have had some sleepless nights trying to figure this out, the only thing i can think of is that one of my pumps has been running for quite some time now. Is it possible that it might have been running to long without being cleaned, and that it is starting to produce some kind a poison ?
I am going to clean this pump tonight, just to be sure.
But if there is anyone that have experienced this or have any help to offer
i would be very happy, this is killing me

Regards
Tom