I've recently returned to the hobby of keeping large American Cichlids after many years of being away. I figured a good introduction to the hobby for my young son would be to raise up a small Oscar to adulthood. We picked up a very small 2" Oscar about 9 months ago at our LFS and grew him out to a fat, healthy, happy outgoing 8" specimen.
Recently I painted and did some light remodeling in the room the fish is located in. I took the opportunity to upgrade to a much needed larger aquarium since I had to move the tank anyways.
Since then, the fish has been highly aggressive and extremely stressed. Hardly eating, attacking his reflection, charging me and changing colors drastically. Gill flaring, laying on his side, etc. Now, I am not new to large Cichlids nor this behavior but I have not witnessed this to this extent. Ther fish has been acting (without pause) like this for about two weeks now. I am concerned that the stress will effect the fishes health sooner rather then later. There's already a few scales missing and the fish has eaten only three times in two weeks. Prior to the change, this fish would splash water to get my attention and then swim to the front corner of the aquarium and wait for a meal.
Here are my thoughts: The fish is still adjusting from the change in environment and will settle eventually. Or, I'm using black window cling on the rear of the aquarium instead of paint (as I usually paint the rear of my aquariums) and the cling is not washing out the reflection and maybe increasing it. The fish is constantly attacking the reflection. And possibly, the fish is entering sexual maturity and this is normal.
There's no tankmates. The decor consists of a tile slate bottom and a piece of driftwood with a really really old anubias plant grown on it. I use a powerhead for flow and an air driven sponge filter - I'm old school that way. The water parameters are perfect with Nitrates being below 10ppm and I do large water changes 2x weekly. Apprx 50%.
Thoughts, feelings, and ideas?
Personally, I'm considering draining the aquarium and painting the rear, sides and bottom to resolve the reflection issue as much as possible.