Dead and dying fish

[lukkereynolds]

hey I’m in need of help,, I have a roughly 3 month old 20 gallon tank,, woke up yesterday morning to a dead purple fire fish which had no signs of obvious death,,I then checked parameters which where perfect ,, Ph- 8.2 ,, KH- 9,, Salinity- 1.025,, Nitrite-0,, nitrate-10,, phosphate-0.04,, ammonia was ,, I then couldn’t find my royal gramma which I later found laying down belly up in a rock,, as I went to remove him he swam very poorly,, so I took him out and put him in a temporary tank where he died around a hour later,, I then checked peramiters again which had not changed he did appear to have nipped at fins however,, this morning now my clownfish appear to be acting very weird ,, my corals however are perfect clownfish are hiding swimming very lathargically and just overall don’t appear to be in good health,, they had a white string hanging from there stomach which I just took as fish poop but am in need of help as I don’t want to loose them too!

 

[davidcalgary29]

I'm sorry for your losses. The first thing that you should do is take a short video -- with white lights -- of the fish, and post it here.

The second thing you should do is consider setting up a hospital tank. It need not be a complicated thing: a plastic tote or garbage bin will do, along with a powerhead, heating source, and some type of filter. If you do need to treat your fish, you should almost never do that in your display tank.

 

[Sharkbait19]

As said, if you could attach pictures and videos it would help tremendously. How long have the fish been in the tank? When was the most recent addition?
Have the fish been eating, and what have you been feeding them? White poop can mean a lot, whether benign or a classic sign of internal parasites.