Fish are dying

[Corydora0101]

Lost 5 corydora in 1 week, only addition was 4 julli last week... thats when it all went downhill.. heavily planted 54gal community tank. Twice a week 25-30% water changes. Low stocked.. did ammonia and was 0.25ppm but I've got alot of dying stock.. whats going on? I'm doing a 50% w/c right now.

 

[Mii]

do your fish show any symptoms, signs of disease, or injury? or did they just drop dead for no apparent reason? 0.25 ammonia certainly isn't helpful, but shouldn't be enough to kill your fish.

 

[Corydora0101]

Not at all, the only abnormality is the blue cloudy eyes I saw and the cory most recently dead was swimming upside down on the surface.

 

[Mii]

Not at all, the only abnormality is the blue cloudy eyes I saw and the cory most recently dead was swimming upside down on the surface.

I have no clue what's wrong with your fish, hopefully someone who does will come along and can be more helpful than me.

 

[Corydora0101]

I just did a 50% w/c and cleaned out 3 more dead fish.. so maybe cleaned out all that and doing the dramatic w/c will stop whatever is going on.

 

[Frank the Fish guy]

0.25 ppm ammonia is actually harmful to fish IF your pH is above about 8.4. If your pH is even higher, near 8.7 the ammonia at this level is deadly.

So ammonia levels are not enough, you need to also measure your pH to eliminate this is a cause.

Here is a handy table: