Additonal filter added, now fish won't eat.

[saltydog]

I was experiencing elevated ammonia & nitrite levels in a highly populated tank & so added second filter- a Magnum HOT.
Ever since, Pacus, normally greedy eaters who are never satiated, have refused to eat. Tin-foil barbs & giant danios are fine. Ammonia & nitrite levels are O. PH is 6.6 which is typical for this tank. Last 20% water change was about the same time that filter was added. Tank water level is kept low as Pacus splash a lot &, at present I cannot put on a lid. This low level results in a lot of waterfall noise from the HOT filter. Is it possible that this noise or the visual presence of this filter is disturbing these fish. (However, they actually tend to congregate around it.) Any other ideas?

[s0me]

I'm not a fish psychologist but I would be under the impression that perhaps they are just "spooked" by the new sound and environment. I was reading somehwere that fish do not like new environments, and it takes awhile for them to adapt.

I would suggest just waiting a week or so, and see if their eating and other habits go back to normal. If not, I would suspect the filter.

Maybe try and remove it in a weeks time if you don't see any changes in the habits.

Just my two cents worth.