My tiger oscar (Chomp Chomp) has always been very aggressive, but lately his aggression has become progressively worse. He has been jumping out of the water to bite people and sometimes he wakes me up in the middle of the night by splashing and smacking the aquarium lid. Because of his nature, I removed all the decorations in his tank that could possibly hurt him.
Last night, something awful must have happened because this morning I found him with the entire top of his head scraped off and bleeding. I assume he hit the lid and somehow hurt himself.
I was wondering if I could somehow cover the entire underside of the lid with foam or sponge to prevent another accident like this from happening again, but I'm not sure what kind to use because I'm afraid of toxins in these materials.
Does anyone have any suggestions? Please help! Thanks

By the way, he is in a 55 gallon tank by himself.

there are times oscar become aggressive for some reasons. for that we need
to know your water parameters: ammonia" nitrites? nitrates? pH ? temp?

if you believe the injury comes from hitting the cover lid, try to lower down
water level to lessen the chance of hitting the rim again. fishes sometimes
darted away, or try to jump when trying to either escaping some irritants
inside the tank or trying to explore the horizon beyond those gap between covers.

Sorry I should have included all of that! Nitrate and Nitrite levels are both at 0 ppm. The pH is between 6.8 and 7, and I use a heater to keep the temperature around 78 degrees. I do water changes once a week, and I also have a 75 gallon biowheel filter. I'm not sure if his water is the problem, I think he's just curious what's outside his tank!

yeah i believe it is more on exploration of horizon beyond
those gap..... i was told by some people that fishes see those
gap as another area of water, thus, they try to get in there...
resulting to jumping out of tank....

with pristine water and good feeding habits, the wound will heal
in no time. some pure salt can help in lieu of antibio meds.

Do you think that I should try to cover the bottom part of the lid with some kind of soft material?

no need, just lower your water level to minimized chance of hitting the same,
plus don't give a gap in-between cover and rim barrier.

He jumps really high, but I'll try and see if that helps! Thanks so much!

mind you, my 14 inches oscar jump over a 7 inches tank rim barrier and i found
it dead on the floor the following morning.

Yeah I'm thinking of using velcro to keep the lid shut because I'm afraid of that happening. Sorry about your oscar.

hellofromtara wrote:


Your Nitrate is 0? What is your ammonia level?

I don't remember exactly what the ammonia was then, but it's around 0.5 right now.