why did my fish die overnight?

[LesGBK]

I have a tank of about five gallons,four fish stayed healthy for three months.But just this morning I noticed that a fish had gone missing and had not appeared outside the tank.Has this ever happened in your tank and do you know why?
by the way,I am just a highschool stundent in China,maybe I will be poor at English grammar,please forgive.
attach a picture of my fish.

 

[Fish Think Pink]

I have a tank of about five gallons,four fish stayed healthy for three months.But just this morning I noticed that a fish had gone missing and had not appeared outside the tank.Has this ever happened in your tank and do you know why?
by the way,I am just a highschool stundent in China,maybe I will be poor at English grammar,please forgive.
attach a picture of my fish.

So perhaps if you have not found a body, perhaps your fish is only hiding. I will remain optimistic it is still alive.

However, have you changed anything recently? With just 5 gallons, are you maintaining evaporation with clean water to maintain salinity? If you might share more information about water parameters, perhaps we might help you figure something out.

It looks like a beautiful fish. I hope it is still alive and just hiding.

 

[blaxsun]

Whenever a fish disappears, it's on the floor, in the sump, somewhere in the rocks or someone availed themselves to a free meal.

 

[Sharkbait19]

What are the other tankmates? Other damsels? Clowns?
If there were rather aggressive fish, it’s possible it was killed and the clean up crew took care of the body.

 

[blaxsun]

What are the other tankmates? Other damsels? Clowns?
If there were rather aggressive fish, it’s possible it was killed and the clean up crew took care of the body.

4 fish ... 1 cup (pico).

 

[LesGBK]

Whenever a fish disappears, it's on the floor, in the sump, somewhere in the rocks or someone availed themselves to a free meal.

Maybe its been eaten by three other fish。。。。

 

[LesGBK]

4 fish ... 1 cup (pico).

in fact,they are no more than five centimenters in size.maybe you are right,Ishould give them a bigger body of water.

 

[LesGBK]

So perhaps if you have not found a body, perhaps your fish is only hiding. I will remain optimistic it is still alive.

However, have you changed anything recently? With just 5 gallons, are you maintaining evaporation with clean water to maintain salinity? If you might share more information about water parameters, perhaps we might help you figure something out.

It looks like a beautiful fish. I hope it is still alive and just hiding.

Although the tank is small,many SPS are grown in it,so I've been changing the water and cleaning the glass once a week .....
For salinity issues,it has a hydrator for real-time rehydration.
Thank you for caring!!