Aggresive fish

[speedy]

Hi,

I recently bought 6 blue dimonds, they all settled in well and were all feeding normaly. After a week or so i noticed one always hiding and not eating as much as the others after a few days he died. The same happened to two more of my fish. I did notice that i did have an aggresive one amongst then. I was wonering if anyone has any ideas on how to fix my problem?

I got my water tested at my LFSit all seemed ok
PH 6.8
KH 6
Temp 32 degreesC
Nitrate 0
Amonia 0

[the german]

put the temp. down 30 is fine.
they are always some agressive discus amongst them but that doesnt causes death of other fish.
something else what you observed what seems to be ot normal?

[MACCA]

Yes, bring the temp down and set the KH to 3-5

[Merrilyn]

How long have you had the tank running Speedy.

Is it just a new tank, and did you cycle it fully before you added discus.

It is sounding very much like "new tank syndrome" where the tank goes throu cycles of high ammonia, followed by high nitrites and finally a nitrate reading of around 10.

You say your tank has no niotrates. A fully cycled tanks should have at least some nitrate reading.

How often are you doing water changes, and how much do you change at a given time.

I assume you're using a good quality dechlorinator at each water change.