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.