fish dieing one by one

Question
i have a new 55 gal set up with a floval 204.  it has been set up for about 4 weeks.  i stocked it with about 12  Cichlids, from elctric yellow to blue zebras.  my amonia tests great but nitrates r high.  wierd thing is i am loosing one fish every couple of days.  they act great with good appetites.  then i will notice one not eating and being very withrawn from the others.  and within 2 days it will be dead.  they r not doing this at once.  just one at a time, with no signs of agression from other fish.  after one dies another will take its place acting sick and die.

Answer
Hi Smitty,
Sorry to hear about that....

I have a feeling it has something to do with your water quality. Poor water is the number 1# leading cause of fish death and disease. You should make sure your nitrites as well as ammonia are both ZERO.

Nitrates should be kept as low as possible. Below 20 is ideal. higher levels longterm can certainly stress fish.

I'd do daily 50% water changes for now until you can be sure your water tests out OK. Fish dying with no obvious visible diseases raises a red flag towards water quality issues.

Best of luck and I hope this helps!
Karen~