Oscar Tank Mates in 650L Tank

[Lammergeier]

I have a 650L tank that has almost finished cycling that I'm planning to move my baby tiger oscar, Henry (currently 6cm long) and 6 silver dollar fish (~6 - 7cm long) to this weekend. I've had them for around a week, and they are temporarily in a 200L tank while the big one finishes cycling.

I was just wondering about a couple of things:

1: Can I comfortably add any other fish to this tank?

2: If I can add other fish to this tank, what would you suggest? I've been looking at perhaps adding a chocolate cichlid or a severum as I've heard they can co-exist with an oscar fairly well, but I'd love any other suggestions.

[Ged]

You can add other fish to the tank but it depends on what look your going for. Are you looking art adding other cichlids or non-cichlid species?

Have a look at Gav's great video of his Oscars and tank mates.

For me this has always been a standout.

What are the dimensions of the tank?

[Lammergeier]

Thanks for the video, that looks amazing!

I was thinking about adding other American cichlid species, and the dimensions of the tank are 6ft x 2ft x 2ft.

[Ducksta]

Gav's tank was 6x4x3 - so a bit more room to move.
Having said that I have a 6x2 and have a few other cichlids and a saratoga in with a big Oscar.

Pretty well most of the larger South American will be ok with them, some of the bigger centrals can tend towards a bit too aggressive to share, but a few work ok too.
My tank suits me with a couple of bay snook and a couple of severums and an XL male red Geo. "Rio Branco".
A couple of male convicts or jewels will also provide active target fish and will help break up territories.
I think the trick is you either need to have one dominant fish and not much else, or kind of like a 'controlled overcrowding' situation that you might normally associate with a Malawi display. (With "medium" aggressive fish, I wouldn't try it with any of the ultra aggressive Centrals...)
Of course you will need major filtration to take care of the enormous amount of waste these guys produce.
The thing with this kind of tank is it can change any time and you have to hope for the best and prepare for the worst. So you will need to have a divider ready to go - or somewhere to move fish to should any problems break out, and have some general purpose meds for when the fish tear themselves up a bit (or a big dose of salt is my preference)

[Lammergeier]

I think the trick is you either need to have one dominant fish and not much else, or kind of like a 'controlled overcrowding' situation that you might normally associate with a Malawi display. (With "medium" aggressive fish, I wouldn't try it with any of the ultra aggressive Centrals...)

I'm thinking of going with the former option. While I love the look of Gav's tank, I'd be happy having an uncrowded tank.

I'm leaning towards just getting a severum or two and letting everyone have a high amount of space. Would a pair be better, or are severums pretty content to be on their own? Also, the oscar is ~8cm now. I'm assuming oscars grow a bit quicker than severums, so I'm assuming I'd be best off getting a severum/severums that are a little larger (maybe 10cm or so)?

Thanks for the advice!

[Ducksta]

Severums will grow slower but if they start around the same size the oscar probably wont get far enough ahead to try to swallow them.
Starting with them a little bigger would be great if you can source some, but they are one of those fish that only seem to turn up the size of 50c coins or full grown... (That I come across anyway)

[Lammergeier]

Yeah, I've noticed that. The largest one I've seen so far was ~6cm long, which would be an issue as the oscar's growing ridiculously quickly.

Went to couple of LFS today, and was recommended these as possible tank mates:

• Severums
• Geophagus (brasiliensis or surinamensis)
• Jack dempsey
• Thoricthys ellioti
• Firemouths
• Blue acaras

It was also suggested I get at least 'a few' other fish to hopefully break up any potential aggression the oscar would show towards them by both LFS, so it seems like a slightly overcrowded scenario might be a better option. Thoughts?

[Ducksta]

I think they are getting at what I was suggesting.
Even in a tank that size, your options are 1 Oscar alone or 1 Oscar plus another half a dozen or so cichlids.
I wouldn't think about having 2 or 3 fish, as when they square off there is nothing to distract them.
Starting small lets them get used to the space and the tankmates, but is no guarantee so you still need to watch and be ready to move any trouble makers long term.

[Ducksta]

It's worth noting that most anecdotal evidence suggests Oscars are more aggressive to other Oscars than they are to other cichlids (generally)

[Lammergeier]

Yep, that's pretty much what I was told today. Sorry for misinterpreting before haha, I can't into reading comprehension, it seems.

Of the species I mentioned, do you think any of them may be asking for trouble? I know it's all down to individual personalities in the end, but I want to get this tank off to the best start I can to minimise the chance of problems down the line. I'll be keeping the 200L tank as an emergency tank should something go wrong and I need to move one of them quickly, and I'm also going to get a divider for the 6 x 2.

I've heard that about oscars, and when I got mine he had already been beaten up a bit by the other 2 juvenile oscars he was kept with. He healed up completely within a day or so but that immediately put me off getting more than one oscar. I've seen some that get along great, but it's a gamble.

[Ducksta]

All of those species would suit. Although a full grown oscar might try to swallow a full grown firemouth or ellioti.
The braziliensis would probably be the biggest bully there but in a 6x2 I wouldnt imagine any drama.

[Lammergeier]

What about a chocolate cichlid (Hypselecara temporalis)? I've heard quite good things about them.

Anyway, at the moment I'm thinking:

• 1 - 2 severum (how do they go with conspecifics, or are they better as a single severum in an aquarium?)
• 1 Jack dempsey (maybe - I'm a bit worried about aggression with a jack dempsey. I've read quite a few stories about JDs being pretty aggressive, and a few of them killing oscars. The electric blues I've heard are less aggressive, but more prone to health issues. Is that right?)
• 1 chocolate cichlid (maybe, depends on the suitability of the JD, and if it's better to get 2 severum or 1)
• A few smaller Americans - I like the acara and the ellioti so I'm thinking about a couple of each, unless either species is better on its own or in a small group of 3+. If there's any other smaller Americans anyone could suggest - please let me know about them. No convicts though, I've heard enough stories about their aggression that I'd be wary about putting a pair in with my red devil, let alone an oscar (my red devil is a colossal pansy, however).

Thanks for the help Ducksta

[Ducksta]

Any combination of those could work.
Personally I don't attribute a huge amount aggression to JDs, and most of the info that does tends to be quite old (I'm looking at you, Axelrod... From an era where a BIG tank was 200 litres and REALLY aggressive fish never made it out of holding tanks)
But, the beauty of these fish (all) is that they have individual personalities and it's impossible to know for sure.
My suggestion is buy the stuff you like the look of that turns up, and thin the population down as they grow and if any fish shows overt aggression, it's the one to go first.

[Lammergeier]

Hey, just an update - I put the oscar and the silver dollars in the 6 x 2 x 2 a couple of days ago. I've grown pretty attached to them all (especially the oscar) since I got him, and decided that the risk of adding other cichlids (even relatively passive ones) was a bit too high for my liking.

There's just something really pleasing about seeing small fish in a big tank, and they all seemed so happy swimming around and exploring that I've decided to go with the one dominant oscar, and just get a few more silver dollars (making 10 SDs in total).

Thanks again for the help! I'll definitely take your advice on board if (probably when) I decide to give a relatively peaceful South American cichlid community a shot.

[Ducksta]

I'm sure you'll have many years of service from a happy Oscar!

[Lammergeier]

That's the plan!

[fullychichlid]

Oscars are great. Enjoy him

[Lammergeier]

Definitely! He's settled in a lot better than what I thought he would tbh. I thought oscars took a while to get used to new surroundings, but I've been handfeeding him since 3 days after I got him, and now it's gotten to the point that if I'm in the dining room, he's doing a 'feed me' dance at the front of the tank, and following me around as I walk past. Doesn't even care if I'm using the gravel siphon - just checks it out then gets in my way begging for food when I'm trying to clean.

Just a quick question regarding oscar growth: I know oscars grow quickly, but mine was 6cm when I got him 3 weeks ago, and as of tonight he's just shy of 10cm. Is that usual? I thought it was ~1 inch a month when they were young.

[Ducksta]

It's not unusual. Especially given space and clean, clear water with not much contention for food.