They have been in for just over a week.
The guppies about 6 weeks.
Pwc done every week without fail. Tapsafe used.
Water tests have always been fine.
The tank is 64L. Now before you say it's not big enough, I'm aware of that. An upgrade is being looked into. The damage was already done so to speak.
I'm just concerned as to what killed him.
And where to go from here. I will never buy fish from pets at home again. Two deaths in little over a week.
The other shark appears to have White spots on his tail. At a guess ich?