My clownsfish partner keep on dieying.

[blood_hound]

I have my clownfish for 3 months now. At first I buy 2 clownfish but after a month her mate die 2 weeks later I bought another clownfish and he lasted for a week so I stop for a few weeks on trying to have my clownfish have a mate.. And a week ago I bought another one and now it just died.

What am I doing wrong? Is it possible that my bigger clown is killing her partner?"But I did not see any aggression" And I also did not notice anything wrong with the they eat fine, no heavy breathing, I will just see them dead on my tank.