Ammonia And Nitrite In My Cory Tank

[lychas]

i have had this tank setup for over a year, it origanaly had my sleepy cod in it then he stopped eating and died, the tank was empty for months, just had java moss in it with the filter running, will just last week i got 2 corydoras similis, i had 2 empty the tank 2 clean it, i filled it back up, tested everything, nitrite was 0 and ammonia was .5-1.0 well i tested again today and the ammonia is still .5-1.0 but the nitrite has gone up to .5, is this something to worry about, the fish look fine, they still eat but do sit still a big, i have added another filter, not i have 2 small corner filters, the temp is also about 28c, do you think i have a prob?

also i just tested ph and it has gone up to about 7.6, i have ph reducing stuff but thats only temporary, whats a more permanant solution?

 

[millym]

i would guess that any bacteria in the filter of your tank from your previous fish has died off, so basically your tank is going through a cycle ( see pinned topics for more info on tank cycling,setting up etc in beginners section of forum i think) which is why you now have nitrite & ammonia as you have added your corys. any level of ammonia & nitrite is harmful to your fish & may kill them. you need to do several small water changes( make sure you use chlorine & chloramin remover not straight tap water) over the next couple of days to get the ammonia & nitrite right down . keep a close eye on your ammonia & nitrite levels they should be 0. your corys may not survive even with the water changes but at least you'll give them a chance.
dont worry about the pH its fine attempting to reduce it will just cause more problems for your already stressed fish.