Extremely lethal and mysterious disease killing fish

[TheStripedHermit]

It all started when I added a midas a few months ago and ever since then any new fish I add to the tank will always die after a week or two however it does not affect inverts.

The symptoms displayed are a reduction in appetite but still eating and gently pacing the glass. At the end the fish will suddenly begin to violently dart and scratch itself everywhere with laboured breathing and by this point theres no hope saving it as death comes the next day.

I doubt it's gill flukes as I treated the tank with prazipro and even left it uninhabited for two months before I added fish so ich seems unlikely. My guess is it may be some kind if viral disease but I'm unsure.

Let me know what your guys thoughts are as its unlike anything I've heard of

 

[Rickybobby]

Do they swim into power heads? Possible velvet. I’ve had that happen to be before because I didn’t qt. And yes none of the those fish killing parasites kill inverts