Oscars for the 125

[Rocksor]

Even in a 8 foot tank, severums can be really pissy with each other. I have 2 pairs (3-5" TL) on opposite sides of the tank, and they still find lots of time everyday to flair, lip lock, nip scales, etc. in the middle. They ignore the two other larger fish. Still deciding which pair to rehome at this point.

If you have even seen an SD sprint because it gets spooked, you will wish that you have a tank bigger than 4 feet. Even at 5 feet, a 2" SD and the shoal can come very close to hitting the other side real quick.

 

[DonnyB]

I have an adult male midas flying solo in a 6ft 125, with three AC 500's for filtration. That single male would kill anything I added, I wouldn't even consider adding a female to that tank. (or anything else) Tried that when he was young, it didn't end well for the other fish.

Line of sight breaks, or not, a large adult fish that gets pissed off and becomes territorial in a 6ft tank will find his/her target in a few short seconds. Even if a clay pipe etc is utilized, (that a male can't fit into) not a very great life for the target who is forced to spend a great deal of time in hiding.

I completely agree. What I'm saying is you wouldn't have a chance in hell for a female midas to survive without those sight line breaks in a 4 foot tank. A 6 foot tank with a place to escape for the female gives you a chance. I mentioned midas only as a way of illustrating that there is no place to go in a 4 foot tank so the Oscars will just fight constantly until one dies of stress or a beating. This conversation would be easy if we replaced Oscar with Midas or RD. The tank we're talking about would eventually only be populated by 1 Midas and maybe the Pleco.

 

[DonnyB]

Even in a 8 foot tank, severums can be really pissy with each other. I have 2 pairs (3-5" TL) on opposite sides of the tank, and they still find lots of time everyday to flair, lip lock, nip scales, etc. in the middle. They ignore the two other larger fish. Still deciding which pair to rehome at this point.

If you have even seen an SD sprint because it gets spooked, you will wish that you have a tank bigger than 4 feet. Even at 5 feet, a 2" SD and the shoal can come very close to hitting the other side real quick.

I found the same with SDs in a 4 foot tank... they don't have room to swim and mine just nipped at each others fins. At the end of the day they were ugly as hell and I hated them; it was my fault as a beginner 10 years ago and I would never do it again. I don't think the extra width would make a big difference.

 

[RD.]

I agree about the 4ft tank, but IME 6ft doesn't make much of a difference to a 12"+ fish. That's still only 1-2 swipes of the tail fin from one end to the other.

Even in a 8 foot tank, severums can be really pissy with each other. I have 2 pairs (3-5" TL) on opposite sides of the tank, and they still find lots of time everyday to flair, lip lock, nip scales, etc. in the middle. They ignore the two other larger fish. Still deciding which pair to rehome at this point.

Years ago a buddy in town had 2 adult pairs of Rotkeil sevs in his 550 gallon, that was 8ft long. Both pairs had their own end of the tank, and driftwood etc where they would spawn on a regular basis. And both pairs constantly waged war against each other just as yours are. It never ended, and they had plenty of large fish distractions.

 

[RD.]

I found the same with SDs in a 4 foot tank... they don't have room to swim and mine just nipped at each others fins. At the end of the day they were ugly as hell and I hated them; it was my fault as a beginner 10 years ago and I would never do it again. I don't think the extra width would make a big difference.

Yet you just recommended that a few posts prior. Did I miss something in between?

No one here is being uber conservative in this discussion. HITH would not be so common in this hobby if people would just slow down, take a deep breath, and realize their limitations. Everyone wants to add just one more fish, until something (or everything) goes sideways.

 

[LBDave]

Yet you just recommended that a few posts prior. Did I miss something in between?

No one here is being uber conservative in this discussion. HITH would not be so common in this hobby if people would just slow down, take a deep breath, and realize their limitations. Everyone wants to add just one more fish, until something (or everything) goes sideways.

Good advice. I am getting a second tank and I am considering how to split up fish based on everyone's comments. Maybe not following to the "T" but at least listening.

 

[DonnyB]

Yet you just recommended that a few posts prior. Did I miss something in between?

No one here is being uber conservative in this discussion. HITH would not be so common in this hobby if people would just slow down, take a deep breath, and realize their limitations. Everyone wants to add just one more fish, until something (or everything) goes sideways.

I'm saying you could have 3-4 SDs and with proper maintenance that bioload could be managed (although 2 O's would certainly be pushing the limits). BUT even if Bioload is OK SDs in a 4 foot tank doesn't leave the SDs with enough room to swim and when they don't have room they tend to shred each others fins and turn uber ugly. I guess my early response was only taking big cichlid aggression and well being into account when it came to compatibility.

 

[Stanzzzz7]

Just for context I'm not super conservative on tank size; my focus is on heathy happy fish. Some on this forum take the tank size thing to extremes and would tell you an Oscar can't be in a 4 foot tank at all. I have been told this and while I agree that 6 foot is better I believe I have a very healthy happy Oscar in my 90. When you hear these extreme opinions that conflict with 95% of the information out there it can cause you to dismiss all the advise on threads like this as over-conservative. There isn't much of that on this thread... but a little so my thoughts above are meant to sort through that and not go over the top. But as a disclaimer, these are large cichlids we're talking about from a behavioural standpoint more than one large oscar may not work at all. All you need is one that decides he doesn't want the other and game over. This is just my opinion.

1. 1 Oscar and Big Pleco Nothing else - 4 foot 120 - bioload at capacity but will work.
2. 2 Oscars -- 4 foot 120 - Works from a bioload perspective. Compatibility is your issue.
3. 2 Oscars and SDs - 4 foot 120 - Pushing your bioload but could work with great filtration large water changes.
4. 1 Oscar and SDs - 4 foot 120 - Works.
5. 3 Oscars - I woundn't try it even in a 125 6 foot tank. 3 is a bad # for cichlids but perhaps you have some docile individuals... Pushing your bioload... I wouldn't do it from a bioload perspective without a 150 and only if the 6 foot version. You're just asking for trouble.

There is nothing extreme about saying a 12inch intelligent fish will lead a very dull life in a four foot tank.
Yes it can be done and water quality can be ok too.
I don't believe an Oscar can swim at anywhere near full speed in a four foot tank, so as a result I don't think they can behave the same as they would in a much larger space.
Obviously worse crimes are committed in this hobby and to some a four foot tank is perfectly exceptable. Having said that please don't try to suggest an oscar will have a life long ride of happiness in such a limited space. The tank would also have limited decor and hiding places just to enable the fish enough swimming space. Stimulation and exercise are as important as water quality to these large inquisitive fish. How many times have I read posts about Oscars sulking. Trapped in four feet of water I'm not surprised.
So yes you can keep an oscar relatively healthy in a four foot tank. Is it ideal? I dont think so.
Another point is regarding silver dollars. One of the most skittish and energetic fish in the hobby. The also have very strong shoaling instinct and are only truly relaxed in large numbers. These are another fish that I don't believe truly thrive in tanks of less than 6 foot. Many species grow almost as big as dinner plates, that coupled with the need to be in groups of at least 6 or more rules out anything smaller than 6ft to me. You only have to see a large school in tanks above 200 gallons to see how they can really behave.
If this opinion is regarded as extreme then so be it. Personally I'd call it considerate.

 

[Coryloach]

Diseases are not something fish catch only in the LFS or appear through magic. Scientific research about micro-organisms in RAS systems for example provides data that all common pathogenic bacteria like Vibrio, Aeromonas, Flavobacterium, etc.. are naturally occurring in fish filters and tank water. Research on Mycobacterium(Fish TB) also shows that those bacteria are everywhere but most are pathogenic only in the "right" environment.

From personal experience and research I also believe HITH and spironucleus vortens are naturally occurring. Fish can also come with an Ich parasite without succumbing to it, etc.. ..Generally worms, internal parasites, protozoa, etc.. are naturally occurring in fish in nature and meds can't always remedy them unless they're still in the gut, or in the case of external parasites. Parasitic disease outbreaks only happen in fish tanks due to the unnatural environment those fish are in.

All the power of preventing these diseases is in the fish owner's hands. Bad water quality,overstocking, aggressive or wrong tank mates,etc.... and the disease is lurking there to catch on the fish's weakened immune system. If fish is not kept in an appropriate way, it is not a matter of If but When. One can luck out but only for a short period of time.

I always advise people to look retrospectively at their fish keeping experience. Count the fish you've killed so far....was it worth it....

It is always wise to take the free advise. Smart people don't learn from their own mistakes, they learn from the mistakes of others.

 

[RD.]

I think we all have our own opinions on what a min tank size should be for various species of fish. I personally don't have an issue with someone that gives a single 12" fish 120 gallons to itself. A lot of fish that are kept by themselves, and raised as wet pets may often have more interaction with their keeper, and mental stimulation, than the same fish forced to live in a community of our choosing. I'm not a fish psychiatrist, so I can only go by what I see behaviour wise, and overall health wise in each fish, and in each situation.

Having said that, most people that have seen SD's in large groups, in large tanks, 6ft long or better, know that they don't do well in small groups, or small tanks, 4ft or under in length. It just doesn't work well long term.

Add the incredible bio-load down the road, and my prediction is the entire set up will become toxic over time.

It is always wise to take the free advise. Smart people don't learn from their own mistakes, they learn from the mistakes of others.

I agree, well said.

Good luck to the OP, hopefully some of this helps them reconsider their future plans.