fish dying

[Tank20]

I've had a couple fish struggling to swim, not eating and then die.
Now I've had a seemingly healthy sword die.
Did a half tank (20 gal tank) water change and removed dead amazon sword plant.
All water parameters check within proper range.
Any suggestions?

 

[gilpi]

Can you give more information, how many fish and what kind?
Temperature?
Filtering?
Feeding? (over or under) usually over feeding is a big problem.
Do you change water regularly?

 

[Tank20]

12 fish...4 neons, 4 tetras, 2 small corys, 1 small pleco, 1 remaining sword
temp was around 78 degrees, lowered to 76
feeding is once a day, usually gone within 2 minutes, so I think not over or under
Using a Fluval C3
Do regular water changes with the exception of letting the last interval go a little long

 

[SaraB]

How long have you had the fish? Was your tank cycled when you added them? Did you add them all at once or just a couple at a time?

 

[SaraB]

Amazon swords go through an ugly stage and may even lose a few leaves when they are first introduced to a tank. Do you think that may be the case with your plant?

 

[Tank20]

This is a cycled tank and the fish have been in for quite a while.
I have not added any new fish in the past few months.
The amazon swords have also been in for a while, over 6 months.