Well i bought fish from my local fish farm. they were 3 silver hatchet fish and 1 fire gourami. i acclimated them for 30 minutes all i did was sit the bag in the water. and when i went to sleep i woke up and 1 hatchet was dead and 1 one of them was dieing you could tell because he was swimming slow and he would stick to the filter tube some times. i euthanized it. then when i came back 4 hours later the other one died. I forgot to say before i added those fish i already had 1 albino bristle pleco.and 3 hatchets. so now its been 2 days and all of my hatchets are swimming normal in a school.also my gourami is normal and swimming all healthy. same for pleco so what could have killed them? the tank did have 1.0 of nitries and 0.5 nitrates at the time but if that killed it then why not all my other fish instead of the new ones?
also 0.5 ammonia.