My marbled Angelfish was suddenly dead today. It has been probably at least 3 months since I had a fish die. It (didn't know gender) was in a 20gal (I was getting a 75 gal soon, so the three big fish in my tank would be more suited) My water stats are fine, though it was getting lethargic for the past few days. It used to come up to the front of the tank but now it was paying no attention to me. It was stuck on the filter. 
The body was not strange in any way at death, no holes or anything. It did occasionally get nipped at by 1 of the Tetras and occasionally the Severum, but I hadn't seen it happen in a long time.
Ammonia - 0
Nitrate - 20
Nitrite - 0
PH - 7.2
Other tankmates
3 Bleeding Heart tetras
3 Serpae Tetras
4 Cories
1 (small) Gold Severum
1 (small) Sailfin Pleco
The body was not strange in any way at death, no holes or anything. It did occasionally get nipped at by 1 of the Tetras and occasionally the Severum, but I hadn't seen it happen in a long time.Ammonia - 0
Nitrate - 20
Nitrite - 0
PH - 7.2
Other tankmates
3 Bleeding Heart tetras
3 Serpae Tetras
4 Cories
1 (small) Gold Severum
1 (small) Sailfin Pleco
