I bought 7 young cardinals 2 wks ago and added them to my 6 month old tank, all were happy and eating and active, until day before yesterday one of my old cardinals died (put it down to old age as was about 5yrs old) but last night two of the young new one's died too
, they all looked healthy yesterday morning so I don't understand whats going on
Have a 40 gallon tank with 1 SAE
, 2 dwarf gourami's (still healthy at the mo, wouldn't like those to go
), 4 harlequins, 2 guppy's and now only 7 cardinals
so not overcrowded. Nitrite 0, Nitrate 25ppm ish (colours difficult to read, may be higher) and Phosphate 0.5ppm
The only thing I did differently was perform a blackout last week (I had BGA) did a water change and added some liquid ferts (10ml Plant nutrition +) as my plants weren't doing well. I usually do weekly PWC
After finding the dead fish, I did a quick small water change in case the nitrates were a bit high. Fingers x!
Any ideas/help really appreciated!