silver perch issue.

[LowIsuzu]

I have 5 small silver perch (15cm approx) in a 5x2x2 established tank who are acting very strange. several are hanging around the sump pump outlet at the top of the tank, the other three just hiding under drift wood at the bottom, none of them appear to be eating as there is heaps of sinking fish pellets at the bottom of the tank.

they have been doing this for a couple days now. i did notice a couple of them flashing against the gravel but havnt seen them do it recently since i did a large water change.

i measured nitrite, nitrate and ammonia, with only a small trace of ammonia present. GH is approx 10 (179?)

recently i have added some driftwood which has been leaching tannins into the water. i did scrub them down heavily before adding them into the tank....
also had two bristlenose catfish (10cm) who both died all of a sudden just before this problem occurredd... couldnt find a reason why they died...

ideas people?

[yarra2]

My first thought on reading this was - are you sure the water is well aerated?

Mike

[wombat1100]

what is the ammonia level?
are the fish gasping quickly as they breath?

[cichlidboy]

any surface agitation in your tank?
ammonia readings?...
has the weather there been crazy lately?
anything under 14 degrees or so and fish tend to slow down a lot.
even cold water fish.

[cichlidboy]

have you cleaned up the uneaten food yet? do a water change chuck a heater in there if you dont already have one. and if you do whats the temperature at?>

[LowIsuzu]

Yes, i did clean up all the uneaten food. did another small water change and removed all the driftwood. i have seen most of the fish eat today, but they dont seem as excited about it as previously. the smallest fish doesnt appear to be eating.

Like i said in my original post, the traces of ammonia, nitrite and nitrate are all minimal as i do frequent water changes. water agitation is quite good. i have the outlet of my filter rippling the top of the water. temp of water is approx 21/22c...

[LowIsuzu]

so, the smaller of the fish passed away this morning. this issue is confusing me...

[wombat1100]

Even low traces of ammonia and nitrite are lethal, get that sorted and I'm sure that will help, don't add more fish till the problem is solved though

[cichlidboy]

any torn fins?
any sort of bullying behaviour from one of the bigger silver perch?

[LowIsuzu]

no torn fins, no bullying. i find it strange that i am having this problem as i have 2 other 4ft tanks with Malawi cichlids in one, and Gourami/neons/barbs (for the wife) in the other, they all get water changed the same time, and they are all good...

[cichlidboy]

hard to say, would probably be able to figure it out if i had a good look at the tank and fish.