Help dying fish!!!!!

[xjojox86]

Over the last 4 days I've had a dead fish everyday first my angel fish day after my female sword just after giving birth then the day after my male pineapple sword and then a neon teta and today it looks like my black ghost knife fish is dying too! They are all losing there colour and getting whiter and whiter except the knife he's just acting strange and Lyin still! But they all seem to be gasping for breath aswell my tank levels are

Nitrate 20ppm
Nitrite 0ppm
Ammonia 0ppm
PH 7.8

So am really struggling as to what is going on in my tank also the pineapple sword had 22 babies last 2 days 4 have died don't know if that's to be expected please help am confused and not sure what to do x

 

[OrangeCones]

Is this a different tank than the one that had 'high levels' in your other thread? What sized aquarium is it? The readings you post show that the tank is cycled, so you should not be having issues related to water quality.

The knife fish is not compatible with the smaller fish. The others may be stressed if he is hunting them at night.

 

[xjojox86]

Hi no it's the same tank I done water changes and stopped using ammonia lock and ammonia was still high woke up the next day done a test and everything was 0 except nitrate so thought I'd done something wrong so took the water the pet store they tested it and it was all good wierd but good but now the fish r dying the knife fish looks on his way out but all the fish that died r bigger than the knife except the neon x

 

[xjojox86]

Sort it's a 125 litre think that bout 27 gal x

 

[xjojox86]

Do u think it could be a disease x

 

[OrangeCones]

Knife fish hunt by using electricity. Even if he does not successfully hunt the fish, he will try.

Your goal is to have zero ammonia, zero nitrite and some measurable nitrate. The high levels you use to have for ammonia and nitrite likely poisoned the fish. The death is not necessarily immediately, but it damages their gills and they cannot take in oxygen. The only fish family that I know of are the danios that can regenerate damanged gills. Any other fish, once the damage is done, its done.