So I just put a batch of 5 cardinal tetras in my 55 gallon. I didn't quarantine them as long as I should've because I had a white lobster in my quarantine tank and he qte a few, so I just went ahead and put the rest in my large tabk before they all got eaten. So it's been about 4 days, and one cardinal has died, as well as a rummynose tetra, and one celebes rainbow. I haven't has a single fish din in MONTHS before adding these guys, do you think they have some sort of disease? None of the fish are showing any signs of illness before dying, I just look in there in the morning or after work and they are on the bottom, gone.