Hi, I'm new to this site and keeping Oscas. I have 2 that i brought 3 weeks ago both about 2 inches long at that time. One has now grown to 3 inches, the other is still about 2 as he stopped feeding for a few days.
They both got on well and spent most of the time swimming together and curling around each other. The larger one tho has become aggressive in the last few days and keeps butting the smaller one who is spending his time up in the corner of the tank, tho still feeding.
My pet shop said to try and feed the smaller fish more than the larger one to reduce the difference in their sizes...easier said than done. I am also wondering if the larger one is hungry and therefore picking on the smaller fish?

A couple of questions:
- the smaller fish has bruises on him from the butting, assuming I can grow him on will the original colouring return?
- should i buy another fish of similar size to my larger one now, in case i lose the smaller one and before the original one becomes to large to accept another fish?

You advice would be very welcome. Thanks,Pete

firstly welcome to the site.

now on to your questions. since your oscars are still juvenile i would assume that the larger one is just trying to be more dominate in the tank. this is normal behaviour in oscars. as long as the injuries dont get to serious i would worry to mcuh about it.
as for if you smaller oscar will regain his colour. i would say yes he will when he heal and finds his spot in the tank.
as for getting another fish to add to your tank it depends on what size your tank is and what all you have in it.
hope some of this helps you.

Looks like necro has you covered, And welcome to the site!

Thanks for your reply. My tank is 240 litres (48" by 15") and I have just the two oscas in it for now, didnt want to over crowd.
From what you've said i'm rpobably behaving like a new mum and worrying about nothing, like you guys i just want the best for my fish.
is three a crowd with Oscas?

yes it is.

its not so much a problem when they are small but when they mature you will more tahn likely run into problems with agression

necro has give you excelent advise........and welcome to the forum

a 240 litre tank works out to be about 50 some gallons and unfortunetly that is not really big enough for one oscars let alone 2. i think you should consider upgrading to a 110 gallon tank if you plan on keeping both oscars.
also if you decide to rehome one of your o's your tank is not large enough for any tankmates to go with him.

jsut thought you should know

Thanks for the info on tank size. In the UK 240 litres is considered a reasonable size but I've checked and can get one for 400 litres (87 litres )
My pet store said my tank would be fine for 2 fish but I respect your more expert view and will look to get as large a one as possible before my fish grow to big. Thanks necro

your pet store is not greedy. some lfs may say you have to
upgrade so that they can sell new tank.

Following necro's advice I've ordered a 110 gallon tank. Assuming i transfer the water from the old to the new tank as my base will it be safe to transfer the fish in whilst the filters are still new?

if you use your existing filter on the bigger tank as well as the new filter you are getting you will be fine to transfer the fish the same day.

no, unless you use all the media in the existing filter.
or you run the new filter in parallel with the old one