dying damsels

[batfire]

I recently set up a 20 gal. species tank to house a mantis shrimp, still waiting for the shrimp. Tank has been running for three weeks, DSB seeded from my 55 setup. I put some cured base rock in also. ammonia 0,
Nitrite 0, Nitrate 5, salinity 1.023. One week ago I added two damsels, they were doing great, eating well. One died yesterday and the second today ???? Temp stays at 78, if it gets real cold at night maybe a max drop to 76. Clueless, TIA

 

[steve-s]

Nothing really stands out although I would suggest a heater. Constantly changing temps are a source of stress. Even though small changes, it's hard to determine the health level of fish sometimes simpley by looking at it. I would suggest making sure no new fish are added for at least 6 weeks just to be on the safe side.

How was the pH and where there any physical symptoms or abnormal behavior?

Cheers
Steve