Losing rainbow fish

[AquaDragon]

A couple weeks ago I got 6 furcata rainbows, 12 PSEUDOMUGIL LUMINATUS rainbows, and 12 ember tetras, and put them in quarantine. 1 week ago I came home to 2 dead rainbows. A week later 2 more died, an 1 died each day for the past 2 days. Ammonia and nitrite are at 0 every time I test. Nitrate is at around 10ppm, ph is at around 6.7, the heater is un plugged and the tank is at 76-78 degrees. I believe it's only the laminatus rainbows that are dying but it's hard to tell them apart from the furcatas so young. I have no meds in the tank but I have melafix, furan 2, and the quarantine trio meds on hand. A few of the dead fish had cloudy bulging eyes but not all of them, so I thought that could be due to how long they were dead for? They are all eating enthusiastically and seem to be acting normal. Any suggestions would be greatly appreciated.

[Colu]

Could be a bacterial infection i  would do a course of furan2 and follow it up with a course of kanaplex in food if your still losing fish after a course of furan2

[AquaDragon]

Thanks for the quick replay, ill try furan when I get home

[laritheloud]

Hi there!

I wanted to share the experience I had with pseudomugils (mine were signifers) in case you're headed in the same direction.

Mine have consistently died off one at a time for the 8 months I've had them. I've treated them with several antibiotics (in food) plus all the major dewormers and antiparasitic meds. They still died off. I am down to the last three, and my last female is on her way out judging by her behavior.

I have since found out that these fish are not very long lived and there's a possibility that they're fairly genetically weak. I haven't been able to come up with an explanation for why they slowly died off, but nothing they have suffered from has spread to my other fish. It is confined only to the pseudomugils.

What I would do is give treatment a try with antibiotics as Colu suggested. If they continue to ail afterwards, just focus on giving them the best life possible; you can try a dewormer, too, if you want to cover your bases. So long as symptoms don't spread to your healthy fish it will probably be okay.