i had my two oscars for over a year now and this odd behavior hasnt happened till this past week. the oscars move all the gravel from one side of the tank to the other side of the tank. i then go and fix it and make it even again and the next day when i wake up all the rocks are moved again. i go to fix it again early in the day so i can see them do this, and what they do is take 2 or 3 at a time and swim to the other side of the tank and drop them.

is this normal?

Perfectly normal behaviour for Oscars, and most Cichlids.

Best you can do is learn to live with it, and not try and fix it for them, because they will change it as they like it, when they like it.


This is generally in my belief why people say you can't have a planted Oscar tank, because they pull the plants out more than they actually eat them.

this is definatly normal! oscars behave much like bulldozers and if they dont like how something is in the tank, they will not hesitate to move things around to their liking!

one thing is certain, if "YOU" thought you had an idea of how the tank was going to be arranged, the oscar has ideas of its own! and believe me when i say the oscar will be alot more persistent about it than you will lol just leave them to their work and when they get it how they like it they will not move stuff around nearly as much, altho i dont think they ever really stop doing that kind of stuff. lol i have fake plants and flower pots, and a plastic tree stump, and none of its where it was when i put it in the tank lol. i have this little ceramic cave, and i stand it up, within an hour the oscar will have pushed it over on its side... ive been standing that cave up for a year now every time i clean the tank... and it gets pushed right back over lol.

its their house! they gonna arrange it to their liking

Win wrote:

How true!
I noticed yesterday that my Vieja was chasing away the Silver Dollars by taking mouthssfull of gravel and spitting it at my SD's!
I've seen the rearanging thing going on before, but throwing stones at fellowfish was a new thing!
Those fish never cease to amazed me!

and you will be more amaze when an oscar scooping a big pc of rock,
swim upward and release the rock, hitting the bottom and break the
bottom plate. it happened to me once while watching. you will be
surprise that your tank water is subsiding.

PAUL wrote:

I don't think "Amazed" is the right word to describe my state of mind at the moment that happens, Paul!
I got no emergency plan for my fish, except putting them into the 90Gl communitytank!
but I'll get my cam to video "Buffet-time" if it ever happens!

thanks for the replies. the only reason i was concerened because i have an under gravel filter along with my 2 penguin 350s on the back of the tank. should i just remove the under gravel filter?

and it looks like the oscars are hurting themselves from pushing the rocks and what not. i did a water change and added salt and turned the temp up to 81-82. hopefully that helps and heals em.

Oscars will arrange the tank how they like it. I actually like the look where the gravel has different depths over the tank

If the remove the gravel all the way down to the UGF plate, the UGF wont work. The solution is to get a gravel tidy. A gravel tidy is a flexable sheet that has small holes in it. What you do is put gravel over the UGF plate, then the gravel tidy and then more gravel on top for the oscars to move

A UGF is unlikely to provide enough filtration for an oscar. If you only have the UGF for filtration i suggest you get a external cannister filter as well

well i have 2 penguin 350s hanging on the tank as well. i am going to buy a canister filter for my tank tho for christmas and a whole new tank altogether. i heard the canisters are better filters than the hang on the back bio wheel ones.

We dont have HOB's in the uk but cannisters are the best

i have used both hobs and canister and from experience i can say that canister are by far a better way to filter an oscar tank.

having used hob's for the past 20 years or so, and just recently moving up to a big xp4 canister, i can truely say WOW what a difference!!!! my water quality stays good 3 times longer than before lol.