I bought 3 blue/green chromis 3 days ago from the LFS. There were no visible signs of diease or wounds. The fish were eating well. Today 2 died witihin hours of each other. 1 is still alive....for now! The dead chromis had a dark purprle bruises on top or by the gills in each case. The last chromi has a similar bruise on top behind his head. I performed a 20% water change. I have a few questions:
1.) What is causing this?
2.) Do I treat the survior?
3.) Does this compromise the small piece of live rock in the QT tank, i.e. do i need to toss it?
4.) Should I just try another set of chromis or do I need to sanatize the QT tank and start over?
20 gallon QT Tank Paramters (prior to 20% water change at same salinty):
Temp = 80 deg
S.G. = 1.025
pH = 8.4
Ammonia = <.25 ppm
Nitrite = <.50 ppm
Nitrate = 10-20 ppm
1.) What is causing this?
2.) Do I treat the survior?
3.) Does this compromise the small piece of live rock in the QT tank, i.e. do i need to toss it?
4.) Should I just try another set of chromis or do I need to sanatize the QT tank and start over?
20 gallon QT Tank Paramters (prior to 20% water change at same salinty):
Temp = 80 deg
S.G. = 1.025
pH = 8.4
Ammonia = <.25 ppm
Nitrite = <.50 ppm
Nitrate = 10-20 ppm