All My Fish At The Top Of The Tank

[mezzic]

For the last couple of days my fish have stayed at the top of the tank (looks like their gasping for air), the last 2-3days i've lost 5 fish and 1 shrimp all looked and acting perfectly normal, i did a 70% water change today and have just check the stats below, am i best of doing another water change any help/advise would be great.

Tank size: 190L community tank
ammonia:0.25PPM
nitrite:20PPM
nitrate:0.50PPM
tank temp:25.2`C

Cheers Mezzic

 

[mattlee]

with ammonia and nitrite as high as they are the fish are probably slowly being poisoned..... keep doing water changes until the ammonia and nitrite read 0. the % of water changed will define the amount of decrease in the toxins ie ammonia 1 with a 50% water change will reduce it to 0.5.
did you cycle the tank before adding the fish?

 

[Miss Dib Dabs]

Oh my. They are indeed gasping for oxygen. Your readings show those of a cycling tank/filter. Get an air stone running in there and keep doing daily water changes until your readings show 0 ammonia and 0 nitrite. Between now and then you can expect some more deaths, and ammonia burns can occur on the fish (skin appears blackened). All of which can lead to further diseases attacking the fish as their immune systems will be compromised.
Best of luck.
P.

 

[mezzic]

the tanks been up and running for nearly 2years now i'll do another big water change now, how long should i wait before checking the stats again

 

[WILDER]

How many fish and which type are in the tank.

Check water stats a few hours later after water change.

 

[mezzic]

stocking is
2 scissortails
1 red tail shark
2 kissing g
10 tetras
4 corys
2 plecs
5 swordtails
4 platys
7 mollys
5 shrimp

ill check the stats after top gear

 

[WILDER]

Your tanks overstocked.
You need to run another filter to cope with all the fish in the tank.
What filter are you running.
How often do you maintain the tank, water changes and gravel vac.

What your tap nitrate reading.
When did you last squeeze a filter sponge in old tank water.