Unresolved my Fish dying from on minut to the next!?

I agree,20 ppm nitrate is hardly bad water quality,some tanks never get under 10/20 (excluding sps systems),a reading of 20 on nitrate would not be toxic enough to really even be stressful to fish,however,it should still be a goal to get your nitrates lower.

 

the interesting thing is i didn't see any sign of him getting bullied? and he didn't have any mark or rip fins?

 

this is why i suspect water quality, or he was diseased when introduced. how big was he?

 

he was about 2"

i also add at the same time a Diamond Goby he even start to sift the sand but sadly he died a few hours after the trigger.

 

+1 damsels are not about to give up some space...in that size tank you are at about max. The bullying is stressful for newly established fish.

 

water

My bet is not on traditional water quality but something else...like does any tap water go into your tank? any non-reef rocks or decor that could be leaching heavy metals? I think there is something poisonous in there that damsels can stand (I think they'd live in the toilet if acclaimated slowly), most likely chlorine/fluoride from somewhere or soap from a dirty bucket. Just my 2 cents....

 

my father who got me into this hobby said that when he was young and first starting with freshwater he mistook a damsel for a FW fish and put one in his 55 gallon tank, he said it lasted several days in there.

 

This makes a lot of cents sins i added dry coral to the tank without rinsing it properly but i dose the tank with chlorine and metal neutralizer.

If this is the storydos it also make cents that the clownfish should live? and how do i get rid of it i did a 100% water change shall i change the carbon?

 

where do you get your new fish? online or lfs. if its online, they might got too stressed in transit.

 

i get it from a lfs